*SHOW British Water Beetles - 9 October 2012.

*CHARACTER LIST
#1. <family nomenclature:>/

#2. <colloquial family names:>/

#3. beetles <whether adults aquatic: water-beetles or land dwellers>/
       1. terrestrial/
       2. sub-aquatic/
       3. aquatic/

#4. beetles <adult locomotion>/
       1. free-swimming and diving strongly, with the main thrust delivered by
          the specially adapted hind legs, moving clumsily on land/
       2. surface swimmers with the main thrust delivered by the specialised
          middle legs, moving clumsily on land (Whirligigs)/
       3. walking in water or free-swimming by conventional ambulatory motion of
          the legs, not diving strongly/

#5. beetles <mode of locomotion in the water>/
       1. rowing and diving in water by parallel-simultaneous leg movements/
       2. moving in the water by <conventional> alternate, walking leg movements
          <not rowing>/

#6. beetles <aquatic, acquisition and transport of air>/
       1. respiring under water via air which is collected posteriorly and
          stored directly under the elytra/
       2. replenishing air for respiration beneath the elytra indirectly from
          that acquired and held in a ventral plastron <(q.v.), which may be
          visible as a bubble on the underside when submerged>/

#7. beetles <aquatic, posture for replenishing air supply>/
       1. regularly posing tail first at the water surface to replenish air/
       2. regularly posing head first at the water surface to replenish air/
       3. not noticeably posing regularly at the water surface to replenish air/

#8. beetles <aquatic, how air is collected>/
       1. collecting air at the water surface by exserting the tip of the
          abdomen through the surface film/
       2. collecting air at the water surface by exserting one antenna to
          achieve a continuum of air with the ventral plastron/
       3. replenishing air in the ventral plastron by exserting both antennae at
          the water surface/
       4. incorporating bubbles of oxygen directly into the <ventral> plastron/

#9. beetles <head-to-tail body length>/
       mm long/

#10. body length/maximum body width/

#11. elytral length/pronotal length <ratio>/

#12. base of prothorax <whether much narrower than elytral bases>/
       1. not or scarcely narrower than the combined elytral bases/
       2. distinctly narrower than the combined elytral bases/

#13. greatest prothoracic width <whether much narrower than greatest elytral
          width>/
       1. not narrower or only slightly narrower than the greatest elytral
          width/
       2. distinctly narrower than greatest elytral width/

#14. <elongate> body <whether widest immediately behind the thorax, or
          distally>/
       1. noticeably widest immediately behind the thorax/
       2. noticeably widest at the rear/
       3. not noticeably widest either behind the thorax, or at the rear/

#15. beetles <body shape, viewed from above>/
       1. <more or less> round/
       2. oval/
       3. elongate-oval/
       4. elongate/
       5. slender/

#16. beetles <rotundity>/
       1. only about 2 to 2.5 times as long as the maximum depth in lateral
          view: globular, less elongate and the elytra more rounded laterally
          than is usual in \i{}Hydroporus\i0{} etc. <<\i{}Hygrotus\i0{},
          \i{}Hyphydrus\i0{}>>/
       2. about 2.5 to 3 times as long as the maximum depth in lateral view: not
          globular, somewhat elongate, the elytra not much rounded laterally/

#17. beetles <presence of paired pronotal and elytral shining hairy bumps>/
       1. characterised by two shining, hairy bumps (tubercles) towards the
          posterior of the pronotum, and a matching pair behind them on the
          shoulders of the elytra <\i{}Macronychus\i0{}>/
       2. without the pairs of pronotal and elytral shining, hairy bumps
          characteristic of \i{}Macronychus\i0{} (q.v.) <<implicit>>/

#18. beetles <overall body shape: flattened, convex or cylindric>/
       1. dorsally flattened/
       2. dorsally somewhat convex/
       3. dorsally strongly convex/
       4. <more or less> cylindric/

#19. beetles <convexity of undersides <from Joy>>/
       1. convex beneath/
       2. flat beneath/

#20. beetles <asymmetric humping>/
       1. asymmetrically humped, and tapered to the rear
          <\i{}Rhipiphoridae\i0{}>/
       2. not asymmetrically humped and tapered <<implicit>>/

#21. beetles <whether the closed elytra are drawn out to form a small point at
          their rear>/
       1. with the closed elytra drawn out to form a very small but distinct
          point at the rear <\i{}Hydrovatus\i0{}>/
       2. with the closed elytra not drawn out to form small point at the rear/

#22. beetles <presence of ventral cavities>/
       1. having ventral body cavities into which the legs fold to conform with
          the general body surface/
       2. without ventral body cavities for reception of the legs/

#23. beetles <whether necked>/
       1. conspicuously necked <distinctly narrowed between head and thorax>/
       2. not necked/

#24. beetles <whether waisted>/
       1. not waisted <parallel-sided, or rounded>/
       2. somewhat waisted/
       3. conspicuously waisted/

#25. beetles <long- or short-legged>/
       1. conspicuously long-legged/
       2. neither particularly long- nor short-legged/
       3. decidedly short-legged/

#26. all the legs <whether very long>/
       1. at least as long as the entire beetle <\i{}Macronychus\i0{}>/
       2. long, but none longer than the entire beetle <<to become implicit?>>/

#27. beetles <colour>/

#28. beetles <brightly coloured or marked>/
       1. exhibiting bright warning colours/
       2. without warning colouration <<implicit>>/

#29. beetles <unicolorous, colour>/
       1. entirely unicolorous yellow/
       2. not entirely unicolorous yellow/

#30. beetles <yellow and black Hydroporinae: marking>/
       1. predominantly black with yellow markings/
       2. predominantly yellow with black markings/

#31. beetles <stripes or spots>/
       1. with sharply defined elytral spots and/or blotches/
       2. with elytral longitudinal stripes/
       3. without sharply defined stripes, spots or blotches/

#32. beetles <luminescence>/
       1. luminescent from distal abdominal sternites/
       2. not luminescent/

#33. upper surfaces of body <vestiture>/
       1. glabrous or subglabrous/
       2. non-glabrous <clothed with distinct hairs, setae or scales>/

#34. beetles <nature of hairines>/
       1. with very short, appressed pubescence throughout/
       2. with more or less raised pubsescence/

#35. upper surfaces of body <vestiture, whether including stiff, erect
          bristles>/
       1. exhibiting stiff, erect, dark bristles/
       2. not bristly <without stiff, erect, dark bristles>/

#36. upper surfaces of body <vestiture, whether including scales or scale-like
          setae>/
       1. exhibiting scales or scale-like setae/
       2. with neither scales nor scale-like setae/

#37. beetles <whether conglobulating>/
       1. rolling into a ball <conglobulating> when alarmed/
       2. not conglobulating <<implicit>>/

#38. beetles <whether clicking>/
       1. clicking and jumping to right themselves when inverted/
       2. not clicking and jumping <<implicit>>/

#39. beetles <presence of rostrum: see Notes>/
       1. equipped with a rostrum/
       2. without a rostrum <<implicit>>/

#40. beetles <whether prognathous>/
       1. prognathous/
       2. not prognathous/

#41. the head <of the beetle, whether visible from above>/
       1. covered by the thorax <i.e., when the beetle is viewed from above>/
       2. not covered by the thorax <<implicit>>/

#42. inclination of the head <from occipital foramen to mouth cavity,
          inclination from the longitudinal axis of the body in the living
          beetle>/
       1. slight <at an angle of less than 45 degrees from the longitudinal axis
          of the beetles body>/
       2. strong <at 45 to 90 degrees from the longitudinal axis of the beetles
          body>/
       3. very strong <more than 90 degrees from the longitudinal axis of the
          beetles body>/

#43. eyes <compound, presence>/
       1. present <<implicit>>/
       2. absent/

#44. eyes <compound, apparent number>/
       1. two <<implicit>>/
       2. ostensibly four <the oft-encounterd partial division into an upper and
          lower eye being complete>/

#45. eyes <whether strongly protuberant>/
       1. strongly protuberant/
       2. not strongly protuberant/

#46. eyes <of Dytiscidae in frontal view: indentation of the front edge>/
       1. vertically straight edged at the front/
       2. with the front edge conspicuously indented above the antennal
          insertions/

#47. eyes <pubescent or not>/
       1. bristly <with interfacetal setae>/
       2. without <interfacetal> bristles/

#48. eyes <finely or coarsely facetted>/
       1. finely facetted/
       2. coarsely facetted/

#49. ocelli <presence>/
       1. present/
       2. absent/

#50. ocelli <when present, number>/
       1. solitary/
       2. paired/

#51. the frons <whether transversely ridged>/
       1. with a transverse ridge between the eyes/
       2. without a transverse ridge between the eyes/

#52. the labrum <upper lip, whether externally detectable>/
       1. externally visible from above/
       2. not externally apparent/

#53. mandibles <presence>/
       1. present <implicit>/
       2. absent or vestigial/

#54. mandibles <presence of mola>/
       1. with a well developed mola/
       2. with a reduced mola/
       3. without a mola/

#55. mandibles <prosthecae, presence and degree of development>/
       1. with well developed prosthecae/
       2. with reduced prosthecae/
       3. without prosthecae/

#56. the mandibular apices <teeth or lobes>/
       1. simple <without teeth or lobes, truncate or rounded>/
       2. bidentate or bilobed/
       3. multidentate or multilobed/

#57. the incisor edges of the mandibles <teeth>/
       1. simple/
       2. with a single tooth/
       3. with two or more teeth/

#58. the maxillae <apical structures, additional to the palp>/
       1. with distinct galea and lacinia apically to the palp/
       2. with a single apical structure additional to the palp/
       3. comprising the palp, without conspicuous apical lobes/

#59. the maxillae <presence of galea>/
       1. with an outer palpiform lobe (the galea) additional to the 4-segmented
          maxillary palp/
       2. without a conspicuous galea <implicit>/

#60. the maxillae <whether with stylet-like lobes>/
       1. with stylet-like lobes/
       2. without stylet-like lobes <implicit>/

#61. the maxillary palps <whether normal>/
       1. normal, flexible/
       2. if visible, short and rigid/

#62. the maxillary palps <whether much shorter than the antennae>/
       1. scarcely visible, being very much shorter than the antennae/
       2. relatively conspicuous <<implicit>>/

#63. the maxillary palps <elongation>/
       1. conspicuously elongated, sometimes longer than the antennae/
       2. not especially elongated <<implicit>>/

#64. the maxillary palps <whether less than twice as long as the antennae>/
       1. less than twice as long as the antennae/
       2. about twice as long as the antennae/

#65. the maxillary palps <elongation>/
       1. conspicuously elongated, sometimes longer than the antennae/
       2. not especially elongated <<implicit>>/

#66. the apical segment of the maxillary palps <shape>/
       1. cylindrical to fusiform/
       2. somewhat expanded and truncate to subtriangular/
       3. securiform to cultriform <axe- to knife-shaped>/
       4. aciculate/

#67. the apical segment of the maxillary palps <relative length>/
       1. shorter than the penultimate one/
       2. longer than the penultimate one/

#68. the apical segment of the labial palps <shape>/
       1. more or less expanded apically/
       2. not expanded apically <cylindrical to fusiform>/

#69. antennae <length relative to length of insect>/
       1. very short <less than a fifth of the insects head to tail length;
          antenna/insect length = 0.1-0.2>/
       2. short <less than half of the insects head to tail length;
          antenna/insect length = 0.2-0.4>/
       3. about half the insect's head to tail length <antenna/insect length =
          0.4-0.6>/
       4. long, but not exceeding the insects head to tail length <more than
          half the insect's length; antenna/insect length = 0.6-1.0>/
       5. longer than the insect's head to tail length <antenna/insect length =
          1.0+>/

#70. antennae <insertion>/
       1. inserted on the front of the head, with the distance between their
          bases no greater than the length of their first segment/
       2. inserted further apart than the length of their first segment
          <<implicit>>/

#71. antennae <whether strongly asymmetric>/
       1. strongly asymmetric/
       2. not strongly asymmetric <including merely elbowed or bent
          <implicit>>/

#72. antennae <whether elbowed>/
       1. conspicuously elbowed <bent>/
       2. not elbowed <<implicit>>/

#73. antennae <number of segments>/
       segmented/

#74. antennae <whether hairy>/
       1. hairy/
       2. not hairy/

#75. antennae <of beetles, presence of scape>/
       1. with the scape much-elongated <a single, elongated basal segment>/
       2. without a much-elongated scape <though it may be longer than the
          adjoining segment <implicit>>/

#76. antennal scape <whether swollen>/
       1. swollen/
       2. not swollen <<implicit>>/

#77. antennae <shape>/
       1. filiform <including moniliform>/
       2. gradually expanding towards the apex/
       3. clubbed/
       4. serrate/
       5. pectinate/

#78. antennal clubs <whether lamellate (laminate)>/
       1. lamellate <laminate>/
       2. not lamellate <<implicit>>/

#79. antennal clubs <number of segments>/
       segmented/

#80. antennal clubs <detailed construction>/
       1. spherical, comprising two small basal segments and a large terminal
          one <\i{}Cerylonidae\i0{}>/
       2. not comprising two small basal segments and a large terminal one
          <<implicit>>/

#81. antennal clubs <whether preceded by a cupular segment>/
       1. preceded by a cupule/
       2. without a cupule <<implicit>>/

#82. antennal segment 8 <length relative to the second>/
       1. shorter than the second/
       2. at least as long as the second/

#83. antennal segment 8 <within the club, whether smaller than 7 and 9>/
       1. <markedly> smaller than segments 7 and 9 <\i{}Leiodidae\i0{}>/
       2. not <markedly> smaller than 7 and 9 <<implicit>>/

#84. antennal insertions <whether visible from above>/
       1. visible from above/
       2. hidden from above/

#85. antennal insertions <whether covered by extensions from the frons>/
       1. hidden by lateral extensions of the frons <\i{}Tenebrionidae\i0{}>/
       2. not hidden by lateral extensions of the frons/

#86. antennal insertions <whether located in fossae>/
       1. countersunk within saucer-like fossae/
       2. not in fossae <flush or raised>/

#87. prothorax <length relative to width>/
       1. shorter than wide/
       2. about as long as wide/
       3. longer than wide/

#88. prothorax <of elongate beetle> at its widest <width relative that of the to
          abdomen>/
       1. markedly narrower than the adjoining part of the abdomen/
       2. not markedly narrower than the adjoining part of the abdomen/

#89. prothorax <presence of a suture between pronotum and propleuron>/
       1. with notopleural sutures/
       2. without notopleural sutures/

#90. pronotal length/maximum pronotal width <ratio>/

#91. the pronotum <shape>/
       1. narrowing <at least somewhat> towards the rear/
       2. not narrowing towards the rear/

#92. the pronotum <longitudinal furrows>/
       1. with five full length, longitudinal furrows/
       2. without five full length longitudinal furrows <ignore pits
          <implicit>>/

#93. the pronotum <with or without two sharply defined ridges>/
       1. with two sharply defined longitudinal ridges/
       2. without sharply defined ridges/

#94. the <pair of> longitudinal <pronotal> ridges <whether incurving
          posteriorly>/
       1. sharply incurving posteriorly, almost meeting adjacent to the
          scutellum <<\i{}Elmis\i0{}>>/
       2. remaining well separated throughout their length/

#95. the pronotum <presence of large pits>/
       1. with large pits/
       2. without large pits/

#96. the pronotum <paired longitudinal furrows adjoining a pair on the elytra>/
       1. with a single longitudinal furrow posteriorly on each side, these
          located two-thirds of the way from the mid-line and adjoining a pair
          of short furrows at the bases of the (closed) elytra/
       2. without the pair of longitudinal furrows characteristic of
          \i{}Hydroglyphus\i0{}, \i{}Bidessus\i0{} et al. (q.v.)/

#97. the pronotum <presence of a single, short median-longitudinal furrow
          towards the outer margin on each side>/
       1. with a single, short median-longitudinal furrow towards the outer
          margin on each side/
       2. without a single, short median-longitudinal furrow towards the outer
          margin on each side/

#98. the pronotum <shortly furrowed on each side>/
       1. with a pair of short longitudinal furrows, one on each side <some
          Hydroporinae>/
       2. without a short longitudinal furrow on each side/

#99. the pronotum <uniform or patterned>/
       1. patterned <more or less conspicuously>/
       2. not conspicuously patterned <uniform>/

#100. the <uniform> pronotum <colour>/
       1. uniformly pale/
       2. uniformly dark/
       3. reddish/
       4. mid-brown/

#101. the pronotum <colouring relative to the elytra>/
       1. paler than the elytra/
       2. coloured similarly to the elytra/
       3. darker than the elytra/

#102. the pronotum <colour patterns: Dytiscidae>/
       1. pale with a broad black crescent at the rear/
       2. with two black bars across the middle enclosing a yellowish one/
       3. pale with black bands on the front and hind margins (sometimes with a
          thin yellow line preceding the front band)/
       4. dark, yellow margined either all round or at front and sides only/
       5. pale, with a broad dark bat-shaped band across the middle/

#103. scutellum <presence: Dytiscidae>/
       1. present <visible at junction of pronotum with elytra>/
       2. absent/

#104. scutellum <relative length>/
       1. much longer than broad <<to become implicit?>>/
       2. not much longer than broad/

#105. the scutellum <elevation>/
       1. elevated <abruptly and fairly sharply above the mesoscutum, in lateral
          view>/
       2. not elevated/

#106. the pronotum and elytra <hairy covering>/
       1. covered with fine hair <<\i{}Orectochilus\i0{}>>/
       2. hairless <<\i{}Gyrinus\i0{}>>/

#107. the mesoventrite <mesosternum, whether keeled or with a posterior point
          <Balfour-Browne>>/
       1. keeled/
       2. not keeled, but with a dorsal point/
       3. not keeled, and without a dorsal point/

#108. metaventrite <metasternum, whether exhibiting a transverse groove>/
       1. with a transverse groove/
       2. without a transverse groove/

#109. the prosternal process <presence>/
       1. present <implicit>/
       2. absent/

#110. the prosternal process <when complete, whether interrupted>/
       1. interrupted/
       2. entire <not interrupted <implicit>>/

#111. the prosternal process <complete or incomplete>/
       1. complete <implicit>/
       2. incomplete <not traversing the fossae>/

#112. the prosternal process <extent of complete posterior extension between the
          countersunk coxae>/
       1. falling short of the mesoventrite/
       2. slightly overlapping the mesoventrite/
       3. moderately or strongly overlapping the mesoventrite/
       4. concealing most or all of the mesoventrite/

#113. the prosternal process <shape>/
       1. arising in a different plane from the prosternum, resulting in a
          distinct ridge at its origin <the neck of the prosternal process with
          a sharply raised edge defining a distinct step (Foster & Friday)>/
       2. arising in the same plane as the prosternum, without a distinct ridge
          at its origin <not stepped>/

#114. the prosternal process <shape>/
       1. elongate-oval, glabrous and slightly domed/
       2. broad, flat and hairy/
       3. narrow and spear-shaped, with a median longitudinal ridge crested with
          curved hairs/

#115. mid-and hind-legs <whether much modified>/
       1. oar-like and much shorter than the fore-legs, which are elongated and
          modified for grasping prey <\i{}Gyrinidae\i0{}>/
       2. not as in \i{}Gyrinidae\i0{} (q.v.) <<implicit>>/

#116. the front tibia <shape>/
       1. very conspicuously asymmetrically expanded and emarginate near the
          attachment of the tarsus <\i{}Megasternum\i0{}>/
       2. more or less club-shaped, not or scarcely emarginate near the
          attachment of the tarsus/

#117. the fore-leg coxal cavites <closed or open behind>/
       1. closed behind/
       2. open behind/

#118. the fore-leg coxal cavities <extent of closure <note inapplicables
          involving the preceding character>>/
       1. broadly open/
       2. narrowly open/
       3. narrowly closed/
       4. broadly closed/

#119. the fore-leg coxal cavities <separation>/
       1. medianly confluent <contiguous>/
       2. narrowly separated/
       3. quite widely separated <by more than 0.4 times their shortest
          diameter>/

#120. the fore-leg coxal cavities <shape>/
       1. strongly transverse/
       2. slightly transverse/
       3. circular to longer than wide/

#121. the fore-leg coxal cavities <presence of lateral extensions>/
       1. with narrow lateral extensions/
       2. without lateral extensions/

#122. the fore-leg coxal cavities <whether closed or open internally>/
       1. internally open/
       2. internally closed by a slender bar/
       3. broadly closed internally/

#123. hind coxae <of beetles, whether movable. Applicable, with caution, only to
          living specimens>/
       1. movable <<implicit>>/
       2. immovably fixed to the metasternum and dividing the first abdominal
          sternite/

#124. hind coxae <lateral extension>/
       1. much expanded and extended laterally to meet the elytra/
       2. not extended laterally to meet the elytra <<implicit>>/

#125. hind coxae <whether posteriorly shaped to receive the femur>/
       1. posteriorly shaped <e.g., declinate or concave> to receive the
          retracted femur/
       2. not shaped posteriorly to receive the femur <<riskily implicit>>/

#126. the hind coxae <whether produced and plate-like behind>/
       1. much enlarged and produced behind into large flat plates which partly
          conceal the hind femora/
       2. not produced behind into flat plates partly concealing the hind femora
          <<implicit>>/

#127. the hind coxal plates <shape>/
       1. smoothly rounded posteriorly, and leaving the last three abdominal
          sternites freely visible/
       2. each with a point on the posterior margin, and covering part of the
          sixth abdominal sternite/

#128. hind coxae <whether steeply, transversely declined>/
       1. with a steep transverse declivity against which the femur retracts/
       2. without the steep transverse declivity characteristic of Dryopoidea/

#129. the inner parts (processes) of the hind coxae <whether contributing to a
          flat longitudinal keel>/
       1. constituting longitudinal plates that are fused to one another and
          joined with the metasternum, endowing the beetle ventrally with a
          flat, median longitudinal keel/
       2. not incorporated with the metasternum in a flat, median longitudinal
          keel <<implicit>>/

#130. the hind coxal <median> processes <relative width>/
       1. very broad, taken together at least as wide as long and forming a
          distinctive plate with a W-shaped hind margin (see illustrations)
          <<Noteridae>>/
       2. longer than broad, the hind margin not W-shaped <pointed, straight or
          wavy (see illustrations) <Dytiscidae>>/

#131. the hind femora <enlargement>/
       1. enlarged for hopping/
       2. not especially enlarged/

#132. the undersides of the hind femora <bristles>/
       1. each with a short comb of bristles (sometimes only three) at the outer
          rear corner/
       2. without bristles at their outer rear corners, or the bristles weak and
          not forming a comb/

#133. hind tibia <of Dytiscidae, form>/
       1. longer than wide, and longer than the relatively slender spurs/
       2. scarcely longer than wide, with one spur massive relative to the other
          and both as long as the body of the tibia/

#134. the hind claws <of Dytiscidae, paired or single>/
       1. paired/
       2. single/

#135. the <paired> hind tarsal claws <whether equal>/
       1. more or less equal in length/
       2. very unequal in length/

#136. tarsal segmentation formula <fore-, mid-, hind-leg: ostensible
          segmentation, ignoring any small cylindrical segments obscured by
          lobes on those preceding them>/
       1. 0, 5, 5/
       2. 5, 5, 5/
       3. 5, 5, 4/
       4. 4, 4, 4/
       5. 4, 4, 3/
       6. 3, 4, 4/
       7. 3, 3, 3/
       8. 5, 4, 4/
       9. 4, 4, 5/
       10. 5, 3, 3/
       11. 4, 3, 3/
       12. 0-2, 3, 3/

#137. <presence of tarsi with bilobed segments>/
       1. some of the tarsi exhibiting <one or more> conspicuously bilobed
          segments/
       2. none of the tarsi with conspicuously bilobed segments/

#138. <presence and location of hidden tarsal segments>/
       1. some tarsi with a tiny penultimate segment hidden by distal lobing of
          the fourth and fused to the fifth/
       2. some of the tarsi with a tiny basal segment that is hard to detect/
       3. none of the tarsi with hidden segments/

#139. the front tarsi <reduction>/
       1. present and well developed <<implicit>>/
       2. reduced or absent/

#140. the front tarsi <number of segments, relative to mid-tarsi>/
       1. with <at least> as many segments as the mid-tarsi/
       2. with one segment fewer than the mid-tarsi/

#141. the front tarsi <number of segments, including any hidden segments>/
       1. 3-segmented/
       2. 4-segmented/
       3. 5-segmented/

#142. the front tarsi <conspicuous modification>/
       1. each having the three proximal segments expanded and approximated to
          form a conspicuous rounded disc/
       2. not each exhibiting a conspicuous, expanded rounded disc <implicit>/

#143. the apical segment <of the front tarsi: relative length>/
       1. longer than the rest together/
       2. about as long as the rest together/
       3. shorter than the rest together/

#144. mid-leg tarsi <total number of segments, including any hidden segments>/
       1. 3-segmented/
       2. 4-segmented/
       3. 5-segmented/

#145. mid-leg tarsi <readily visible versus hidden segments>/
       1. pentamerous <with 5 segments, all conspicuous>/
       2. pseudotetramerous <with 4 obvious segments, plus a reduced one>/
       3. tetramerous <with 4 segments, all easily seen>/
       4. pseudotrimeous <with 3 obvious segments plus a reduced penultimate
          one>/
       5. trimerous <with 3 segments, all easily seen>/
       6. with fewer than three segments/

#146. the claws of the mid-leg tarsi <whether appendaged>/
       1. with an appendage <on each>/
       2. not appendaged/

#147. the appendages <of the claws of the mid-leg tarsi, type>/
       1. not or only lightly sclerotized <usually pubescent>/
       2. heavily sclerotized, blade-like/
       3. heavily sclerotized, spine-like or bristle-like/

#148. the claws of the mid-leg tarsi <whether simple or ornamented>/
       1. simple/
       2. one-toothed or bifid/
       3. serrate, denticulate or pectinate/

#149. the claws of the mid-leg tarsi <whether associated with an empodium>/
       1. with an empodium between them <with or without bristles>/
       2. without an associated empodium/

#150. hind tarsi <number of segments, relative to mid-tarsi>/
       1. with at least as many segments as the mid-tarsi/
       2. with one segment fewer than the mid-tarsi/

#151. hind tarsi <number of segments, including any hidden segments>/
       1. 3-segmented/
       2. 4-segmented/
       3. 5-segmented/

#152. hind tarsi <of beetles, whether modified for swimming>/
       1. flattened oar-like for swimming/
       2. not flattened oar-like <<implicit>>/

#153. hind tarsi <presence of swimming hairs>/
       1. equipped with swimming hairs <sometimes requiring careful
          observation>/
       2. without swimming hairs <<dubiously implicit>>/

#154. the first segment of the hind tarsi <relative length>/
       1. longer than the rest of the tarsus/
       2. shorter than the rest of the tarsus/

#155. hind tarsi <relative length of second segment>/
       1. with the second segment longest/
       2. with the apical segment longer than the second/
       3. with the apical and second segments about equal in length/

#156. hind tarsi <relative lengths of apical and second segments>/
       1. with the apical segment only about half as long as the second/
       2. with the apical segment about three-quarters the length of the second/
       3. with the second and apical segments almost equal in length/

#157. hind tarsi <length of apical segment relative to all the rest>/
       1. with the apical segment about equal to segments 3+4, with segment 2
          very short/
       2. with the apical segment longer than segments 3+4, and segment 2 not
          very short but not longer than 3+4/
       3. with the apical segment at least as long as all the rest together/

#158. swimming hairs <general location>/
       1. confined to the hind legs/
       2. on both middle and hind legs/

#159. swimming hairs <when present, presence on tibiae>/
       1. confined to the tarsi/
       2. present on both tibiae and tarsi/

#160. <adult> elytra <presence>/
       1. present <<implicit>>/
       2. absent/

#161. elytral length/maximum width across the elytra <i.e., with the elytra
          closed>/

#162. elytra <whether unusually elongate and tapered>/
       1. individually distinctly tapered to their apices <markedly posteriorly
          separated when closed>/
       2. not individually tapered <<implicit>>/

#163. elytra <when closed, whether meeting on the mid-line>/
       1. meeting along the length of the mid-line <<implicit>>/
       2. not meeting along the full length of the mid-line/

#164. elytra <when closed, length relative to abdomen>/
       1. covering most to all of the abdomen <<implicit>>/
       2. short, exposing several <(2-)3-6> terminal abdominal tergites/
       3. greatly reduced <vestigial>/

#165. elytra <when closed> exposing <number of abdominal tergites>/
       1. no more than part of the terminal tergite <usually the pygidium>/
       2. at least one but fewer than three complete abdominal tergites/
       3. at least three complete abdominal tergites/

#166. the pygidium <exposure>/
       1. at least partly exposed beyond the long elytra/
       2. entirely concealed by the ends of the elytra even when viewed from
          behind/

#167. elytra <whether truncate>/
       1. truncate/
       2. not truncate/

#168. elytra <subquadrate or elongate <Joys character, of dubious use>>/
       1. subquadrate/
       2. elongate/

#169. elytra <shape detail>/
       1. broadest near the base/
       2. broadest near the middle/
       3. broadest posteriorly/

#170. elytra <hard or soft>/
       1. hard/
       2. soft/

#171. elytra <glossy or dull>/
       1. glossy/
       2. dull/

#172. elytra <iridescent or not>/
       1. iridescent/
       2. not iridescent <<implicit>>/

#173. elytra <whether smooth>/
       1. rough/
       2. tuberculate/
       3. spiny/
       4. ribbed <ridged>/
       5. smooth/

#174. elytra <longitudinal ribs (ridges)>/
       1. with conspicuous longitudinal ribs <ridges; exclusive of the sutural
          margin>/
       2. not conspicuously longitudinally ribbed/

#175. elytra <when ribbed, number of ribs on each>/
       ribbed/

#176. elytra <presence of a small tooth near the tip>/
       1. with a very small tooth projecting from the costa near the tip
          <\i{}Nebrioporus\i0{} spp.>/
       2. without the small tooth near the tip that characterises
          \i{}Nebrioporus\i0{} spp. <<implicit>>/

#177. elytra <colouring and marking: smaller Dytiscidae>/
       1. mottled yellow and black <at x 10 magnification>/
       2. dark with yellow spots or bands/
       3. dark with full length, wide pale margins/
       4. uniformly reddish or mid-brown, no more than faintly streaked or
          spotted/
       5. uniformly very dark or black, no more than faintly streaked or
          spotted/
       6. yellow, each with 5-6 coalescing black stripes/

#178. elytra <pattern of pale markings:
          \i{}Graptodytes\i0{}/\i{}Stictonectes\i0{}>/
       1. black with transverse, pale, complexly wavy markings only/
       2. black, with one or more pale longitudinal stripes running from the
          pronotum to near the tip (without the transverse wavy markings
          characteristic of \i{}Stictonectes\i0{})/

#179. elytra <striping>/
       1. longitudinally with distinct dark stripes/
       2. indistictly dark striped longitudinally/
       3. not dark-striped/

#180. elytra <presence of striae, exclusive of sutural striae>/
       1. longitudinally striate/
       2. without longitudinal striae <discounting sutural striae and rows of
          punctures>/

#181. elytra <presence of striae or rows of punctures: Sphaeridiidae>/
       1. with sutural striae only/
       2. striate or with regular rows of punctures/

#182. elytra <transverse striation>/
       1. predominantly finely but rather conspicuously transversely striated
          <transversely sculptured> across lines of punctured striae/
       2. not predominantly transversely striated across lines of puntured
          striae <<implicit>>/

#183. the middle part of the elytra <small and large punctures>/
       1. with approximately equal numbers of small and large punctures
          scattered in the visibly reticulate surface/
       2. with scattered punctures all more or less of the same size, or
          sometimes also with lines of larger ones/

#184. elytra (and pronotum) <punctures and pits>/
       1. with numerous small punctures, and pits 4-5 times their diameter
          scattered among them/
       2. finely punctured, the numerous punctures all about the same size/

#185. elytra <distictive sculpture>/
       1. reddish and elongate, distinctively sculptured with numerous, short
          longitudinal cuts in the reticulated surface <\i{}Liopterus\i0{}>/
       2. not sculptured with numerous, short longitudinal cuts in a reticulated
          surface <not as in Liopterus <implicit>>/

#186. elytra <presence of strong ridges reaching only halfway>/
       1. each exhibiting a pair of strong longitudinal ridges, with one
          extending only halfway from the shoulder <\i{}Stenelmis\i0{}>/
       2. lacking the pattern of longitudinal ridges characteristic of
          \i{}Stenelmis\i0{} (q.v.) <<implicit>>/

#187. elytra <longitudinal ridges>/
       1. each with a single, strong, median-longitudinal ridge/
       2. not exhibiting a single, strong, median-longitudinal ridge <<to become
          implicit?>>/

#188. elytra <presence of sutural striae>/
       1. each with a well marked sutural stria <full length or not, adjoining
          the suture (q.v.)>/
       2. without well marked sutural striae/

#189. the sutural striae <relative length>/
       1. extending almost the full length of the suture
          <\i{}Hydroglyphus\i0{}>/
       2. extending no more than two-thirds towards the rear
          <\i{}Bidessus\i0{}>/

#190. the rear halves of the elytra <grooving near the mid-line>/
       1. each with a distinct groove <elytral suture, sutural stria> alongside
          the rear of the midline/
       2. without a groove alongside the midline/

#191. scutellary striole <of elytra, presence>/
       1. present/
       2. absent/

#192. elytra <vestiture - glabrous or not>/
       1. non-glabrous <i.e., with hairs, bristles or scales>/
       2. glabrous/

#193. elytra <presence of epipleura>/
       1. with epipleura/
       2. without epipleura/

#194. the elytral epipleura <extent>/
       1. reaching to the tips of the elytra/
       2. falling short of the elytral tips/

#195. the elytral epipleura <whether divided into two parts>/
       1. divided into two parts by a distinct ridge at the outer corner of the
          elytron/
       2. without a dividing ridge/

#196. beetles <details of hairiness and microreticulation: \i{}Oreodytes\i0{},
          \i{}Scarodytes\i0{}>/
       1. dorsally microreticulate and hairless/
       2. dorsally shiny and without microreticulation beneath the covering of
          hair/

#197. elytra <presence of microreticulation>/
       1. microreticulate, with a fine impressed reticulum <this often less
          conspicuous in the disc than towards the apex>/
       2. without a microreticulum/

#198. the <elytral> mictoreticulation <pattern>/
       1. regular/
       2. transverse/
       3. longitudinal/

#199. <hind, metathoracic> wings <presence>/
       1. well developed <presumed propellant>/
       2. absent or much reduced/

#200. <hind, metathoracic> wings <spiral rolling>/
       1. with the apical part spirally rolled/
       2. not apically rolled <<implicit>>/

#201. <hind, metathoracic> wings <absence of venation>/
       1. veined <<implicit>>/
       2. without veins/

#202. <hind, metathoracic> wings <anal lobe>/
       1. with an anal lobe/
       2. without an anal lobe/

#203. <hind, metathoracic> wings <presence of a medial fleck>/
       1. with a medial fleck/
       2. without a medial fleck/

#204. the medial fleck <of hind, metathoracic wings, when present, bisection>/
       1. bisected by a vein/
       2. not bisected by a vein/

#205. <hind, metathoracic> wings <fringing>/
       1. fringed with long hairs on the hind margin/
       2. not fringed <<implicit>>/

#206. abdominal tergites <number>/

#207. the end of the abdomen <extension-pointed>/
       1. extended as a long, narrow point beyond the ends of the truncate
          elytra/
       2. not extended as a long, narrow point beyond the ends of the elytra
          <<implicit>>/

#208. exposed abdominal sternites <= ventrites: number>/

#209. exposed abdominal sternites <articulation>/
       1. all articulated and movable/
       2. comprising both fused and movable components/
       3. all fused and immovable/

#210. exposed abdominal sternites immovably joined <= connate ventrites:
          number>/

#211. abdominal segment 8 <with or without functional spiracles>/
       1. with apparently functional spiracles/
       2. apparently without functional spiracles/

#212. the male external genitalia <aedeagus \i{}sensu lato\i0{}, form>/
       1. trilobate/
       2. bilobate/
       3. histeroid/
       4. buprestoid/
       5. adephagan/
       6. staphylinoid/
       7. bostrichoid/
       8. cucujiform/
       9. tenebrionoid/
       10. chrysomeloid/
       11. curculionoid/
       12. not classified/

#213. adults <whether adults predacious>/
       1. predacious <specify prey>/
       2. not predacious/

#214. adults <non-predacious adults, diet>/
       1. necrophagous/
       2. feeding on dried animal remains/
       3. phytophagous <live plant material: specify kinds>/
       4. consuming decaying plant material <other than wood>/
       5. eating dried plant material or stored plant products/
       6. boring into living wood/
       7. consuming rotting wood/
       8. boring into dead wood/
       9. mycetophagous <specify>/
       10. coprophagous/
       11. parasitic <specify>/

#215. adults <non-aquatic adults, habitat>/
       1. in living vegetation/
       2. in decaying plant material/
       3. in rotting wood/
       4. in dried plant material/
       5. under bark/
       6. on lichens/
       7. associated with fungi/
       8. associated with dung/
       9. associated with carrion/
       10. on shed fur or feathers <in nests or burrows>/
       11. associated with flowers/
       12. under stones/
       13. in stored plant products/

#216. <habitats>/

#217. the larvae <general form>/
       1. campodeiform/
       2. eruciform/
       3. scarabaeiform/
       4. apodous/

#218. the larvae <outline shape, viewed from above>/
       1. strongly flattened and disc-like/
       2. neither strongly flattened nor disc-like <implicit>/

#219. the larvae <shape, viewed from above>/
       1. elongate and more or less parallel-sided/
       2. oblong to ovate <not parallel-sided>/

#220. the larvae <whether C-shaped in lateral view>/
       1. C-shaped in lateral view <strongly curved ventrally>/
       2. not C-shaped <more or less straight ventrally: implicit>/

#221. vestiture <of the larva, nature>/
       1. restricted to fine hairs or setae/
       2. not restricted to fine hairs or setae <e.g., including bristles,
          scales, expanded or complex hairs>/

#222. the larvae <dorsal pigmentation>/
       1. dorsally heavily pigmented or sclerotized/
       2. only very lightly pigmented or sclerotized/

#223. the larvae <ventral pigmentation>/
       1. more or less heavily pigmented/
       2. only very lightly pigmented/

#224. the antennae <of the larva, number of segments>/
       segmented/

#225. the antennae <of the larva, length relative to the width of the head>/
       1. less than 0.15 x the <maximum> with of the head/
       2. 0.15-0.5 x the head width/
       3. more than 0.5 x the width of the head/

#226. stemmata <on either side of the larval head, 6 or fewer>/
       1. 6/
       2. fewer than 6 <specify number>/

#227. the <mature> larval fronto-clypeus <of the head, extension>/
       1. much extended forwardly/
       2. not extended forwardly <<dubiously implicit>>/

#228. frontoclypeal suture <of the larva> between frons and clypeus <presence>/
       1. indistinct or absent/
       2. distinct/

#229. the labrum and head capsule <of the larva, distinction>/
       1. separated by a complete suture/
       2. partly fused, with an incomplete suture/
       3. completely fused, with no suture apparent/

#230. apices of the mandibles <of the larva, toothing or lobing>/
       1. with a single lobe or tooth/
       2. bilobed or bidentate/
       3. trilobed or tridentate/
       4. multilobed or multidentate/

#231. the maxillary palps <of the larva, number of segments>/
       segmented/

#232. the labium <of the larva, presence of a ligula>/
       1. without ligula between the palps/
       2. with a short ligula between the palps/
       3. with a ligula at least as long as the palps/

#233. the labial palps <of the larva, number of segments>/
       segmented/

#234. the mesothoracic legs <number of segments>/
       segmented/

#235. the tarsi <of the larva, number of claws>/
       1. 1-clawed/
       2. 2-clawed/

#236. the mesothoracic legs <number of movable claws>/
       1. with 1 movable claw/
       2. with 2 movable claws/

#237. visible abdominal segments <of the larva, number>/

#238. tergum 9 of the abdomen <of the larva, ventral extension>/
       1. entirely dorsal/
       2. extending to the underside/
       3. completely ventral <LW to pursue this>/

#239. the larvae <whether aquatic>/
       1. aquatic/
       2. non-aquatic <<implicit>>/

#240. the abdomen <of the larva, presence of functional abdominal spiracles>/
       1. exhibiting functional abdominal spiracles/
       2. without functional spiracles <these either lacking, or reduced and
          apparently non-functional>/

#241. the abdomen <of the larva, of functional spiracles on anterior segments>/
       1. having functional spiracles on anterior segments/
       2. with functional spiracles confined to the <posterior pair on> the
          eighth segment/

#242. the abdomen <of the larva, whether spiracles borne on lateral spiracular
          tubes>/
       1. with the spiracles on the eighth segment borne at the ends of
          spiracular tubes/
       2. with anterior and 8th-segmental spiracles borne at the ends of a
          series of spiracular tubes/
       3. without spiracular tubes/

#243. the larvae <presence and form of gills>/
       1. with dorsal, balloon-like tracheal gills on abdominal segments 1-8/
       2. with long and narrow lateral gills on abdominal segments 1-7/
       3. with long and narrow lateral gills on abdominal segments 1-9/
       4. with ventral abdominal gill tufts on abdominal segments 1-3/
       5. with ventral abdominal gill tufts on abdominal segments 1-4/
       6. with anal <abdominal> gill tufts/
       7. without <abdominal> gills <implicit>/

#244. the abdominal apex <of the larva, presence of a respiratory chamber>/
       1. with a respiratory chamber, formed from the 8th and 9th terga and
          enclosing a pair of enlarged spiracles/
       2. without a respiratory chamber/

#245. abdominal tergum 8 <of the larva: armature, spiracles>/
       1. bearing a single median process with a pair of spiracles at its apex/
       2. bearing a single <simple> median process without apical spiracles/
       3. bearing a pair of processes, each with an apical spiracle/
       4. without amature <lacking processes>/

#246. the posterior segments <of the larva, presence of swimming hairs>/
       1. with swimming hairs/
       2. without swimming hairs/

#247. the last abdominal segment <of the larva, presence of cerci (urogomphi)>/
       1. with cerci <urogomphi>/
       2. without cerci/

#248. the last abdominal segment <of the larva, presence of a median spine>/
       1. with a long, median spine <\i{}Hygrobia\i0{}>/
       2. without a long median spine <<implicit>>/

#249. the larvae <whether predacious>/
       1. predacious/
       2. not predacious/

#250. the larvae <non-predaceous, diet>/
       1. necrophagous/
       2. feeding on dried animal remains/
       3. phytophagous <live plant material: specify kinds>/
       4. consuming decaying plant material <other than wood>/
       5. eating dried plant material or stored plant products/
       6. boring into living wood/
       7. consuming rotting wood/
       8. boring into dead wood/
       9. mycetophagous <specify>/
       10. coprophagous/
       11. parasitic <specify>/

#251. the larvae <non-aquatic habitat>/
       1. on living vegetation/
       2. in decaying plant material/
       3. in rotting wood/
       4. in dried plant material/
       5. in or under bark/
       6. on lichens/
       7. in fungi/
       8. in dung/
       9. in carrion/
       10. in shed fur or feathers <in nests or burrows>/
       11. associated with flowers/
       12. under stones/
       13. in stored plant products/

#252. <descriptive comments on larvae>/

#253. <species worldwide, number>/
       species worldwide/

#254. genera <worldwide, number>/

#255. <number of species in Britain:>/
       species in Britain/

#256. genera in Britain <number>/

#257. <genera in Britain:>/

#258. recorded from <distribution in the British Isles>/
       1. Scotland/
       2. Northern England/
       3. South-west England and Wales/
       4. South-eastern England <including East Anglia>/
       5. Ireland/

#259. Suborder/
       1. Adephaga/
       2. Myxophaga/
       3. Polyphaga/

#260. Infraorder <of Polyphaga>/
       1. Bostrichiformia/
       2. Cucujiformia/
       3. Elateriformia/
       4. Scarabaeiformia/
       5. Staphyliniformia/

#261. Superfamily <cf. Unwin, 1984>/
       1. Bostrichoidea/
       2. Buprestoidea/
       3. Byrrhoidea/
       4. Cantharoidea/
       5. Caraboidea/
       6. Chrysomeloidea/
       7. Cleroidea/
       8. Cucujoidea/
       9. Curculionoidea/
       10. Dascilloidea/
       11. Dermestoidea/
       12. Dryopoidea/
       13. Elateroidea/
       14. Eucinetoidea <Scirtoidea>/
       15. Lymexyloidea/
       16. Sphaeroidea/
       17. Histeroidea/
       18. Hydrophiloidea <Palpicornia>/
       19. Scarabaeoidea/
       20. Staphilinoidea/
       21. Tenebrionoidea <Heteromera>/

#262. <family>/
       1. Dryopidae/
       2. Dytiscidae/
       3. Elmidae/
       4. Gyrinidae/
       5. Haliplidae/
       6. Heteroceridae/
       7. Hydraenidae/
       8. Hydrophilidae/
       9. Hygrobiidae (Paelobiidae)/
       10. Limnichidae/
       11. Noteridae/
       12. Psephenidae/
       13. Scirtidae/
       14. Spaeriidae/

#263. Subfamily <of Dytiscidae>/
       1. Agabinae/
       2. Colymbetinae/
       3. Copelatinae/
       4. Dytiscinae/
       5. Hydroporinae/
       6. Laccophilinae/

#264. Subfamily <of Hydrophilidae>/
       1. Georyssinae/
       2. Helophorinae/
       3. Hydrochinae/
       4. Hydrophilinae/
       5. Spercheinae/
       6. Sphaeridiinae/

#265. e.g., <scientific and common names of British representatives>/

#266. <general comments>/

#267. <summary of generic characteristics>/

#268. <family or generic description>/
       1. family description <implicit>/
       2. generic description/

#269. abbreviated taxon name:/

#270. <illustrations:>/
