*SHOW ~ The families of British Non-marine Molluscs. 15 March Februry 
2007. 
 
*CHARACTER LIST 
 
#1. <presence or absence of shell, and its constitution: slug, snail,
          limpet or mussel>/
       1. snails, with a conspicuous, spiral, univalve shell <this
          serving as a shelter or retreat for the animal>/
       2. limpets, with a conspicuous, protective patelliform shell
          bearing only a vestigial spire/
       3. slug-like, but with a small, posterior external shell covering
          the mantle <the shell far too small to contain the animal>/
       4. slugs, with no external shell/
       5. mussels, enclosed by a hinged, bivalve shell <the animals
          lacking a developed head>/
 
#2. <head-to-tail length of fully grown slug>/
       mm long when fully extended/
 
#3. <slugs with no external shell, form of the internal shell>/
       1. with a small, totally internal, symmetrical shell/
       2. with a small, totally internal, asymmetrical shell/
       3. with a degenerate internal shell <sometimes reduced to a few
          granules>/
 
#4. <slug, whether relatively small and wormlike>/
       1. relatively small, slender and almost worm-like when fully
          extended <\i{}Boettgerilla\i0{}>/
       2. not slender and worm-like when extended <implicit>/
 
#5. <slugs, whether assuming a hemispherical or sub-globular form when
          molested>/
       1. contracting protectively into into a hemispherical or
          (\i{}Geomaculus\i0{}) sub-globular form when molested
          <Arionidae>/
       2. contracting protectively when molested, but not assuming the
          hemispherical or sub-globular form characteristic of
          Arionidae/
 
#6. the body <of the slug, colouring>/
 
#7. the mucous <of slugs, colour>/
       1. colourless/
       2. milky/
       3. yellow or orange/
       4. colourless from the foot, and yellow or orange from the body/
 
#8. the mantle <of slugs, posterior or anterior>/
       1. posterior, and covered by the small external shell/
       2. anterior and large <enclosing the shell>/
 
#9. the mantle <patterning>/
       1. exhibiting a large dorsal island, demarcated by a conspicuous
          groove/
       2. with a fingerprint-like pattern of fine, concentric rings
          <folds>/
       3. with neither a dorsal island demarcated by a groove, nor a
          fingerprint-like pattern of folds/
 
#10. the mantle <symmetry of the concentric rings>/
       1. with the concentric rings centred on its mid-line
          <\i{}Limacidae\i0{}>/
       2. with the concentric rings centred to the right of the
          mid-line, above the respiratory pore
          <\i{}Agriolimacidae\i0{}>/
 
#11. the animal <number of tentacles>/
       1. with one pair of <retractable, but not invaginable> tentacles
          only/
       2. with two pairs of <invaginable> tentacles/
 
#12. eyes <presence>/
       1. present <implicit>/
       2. absent <the animal blind>/
 
#13. eyes <position>/
       1. at the tips of the <longer> posterior tentacles/
       2. at the bases of the <only pair of> tentacles/
 
#14. the jaw <\i{}Zonitidae\i0{} type>/
       1. arcuate, with a vertical central keel ending in a median
          projection on the lower edge <\i{}Zonitidae\i0{} and
          \i{}Limacidae\i0{} only>/
       2. not as in \i{}Zonitidae\i0{} and \i{}Limacidae\i0{}
          <implicit>/
 
#15. the jaw <entire or of distinct plates:
          \i{}Punctidae\i0{}/\i{}Discidae\i0{}>/
       1. of a single piece <\i{}Discidae\i0{}>/
       2. of 19 separate plates <\i{}Punctidae\i0{}>/
 
#16. the respiratory pore <pneumopore, in the slugs mantle>/
       1. towards the anterior right of the mantle/
       2. towards the posterior right of the mantle/
 
#17. <attachment to the substrate>/
       1. attaching to stones, etc., via a byssus <a fibrous beard>/
       2. without a byssus/
 
#18. the tail <of the slug, whether dorsally keeled>/
       1. dorsally sharply keeled, the keel reaching to the mantle/
       2. not dorsally keeled/
       3. dorsally bluntly keeled, but the keel falling short of the
          mantle/
 
#19. the mantle <of the snail>/
       1. partly covering the shell when the animal is in motion/
       2. not extending over the shell <implicit>/
 
#20. the shell <univalve, presence of an operculum: see Notes>/
       1. operculate <with a true operculum: see Notes>/
       2. with a clausilium, which functions as an operculum when the
          animal retracts/
       3. inoperculate <and without a clausilium>/
 
#21. the shell <when helically coiled, form>/
       1. planispiral <with a flush or sunken spire>/
       2. rising-spiral/
 
#22. the shell <spiral, number of whorls>/
       whorled/
 
#23. the <coiled> shell typically <sinistral or dextral>/
       1. sinistral/
       2. dextral/
 
#24. the animal <limpet, sinistral or dextral>/
       1. sinistral, with the genital orifice and anus opening on its
          left side, although the vestigial spire of the shell is
          slightly twisted to the right/
       2. dextral, with the genital orifice and anus on its right side,
          although the vestigial spire of the shell inclines to the
          left/
 
#25. the shell <maximum dimension when fully grown>/
       mm in its maximum dimension <height or breadth>/
 
#26. the shell <whether higher than wide>/
       1. higher than wide/
       2. about as high as wide/
       3. wider than high/
 
#27. the shell <height>/
       mm high/
 
#28. the shell <width>/
       mm wide/
 
#29. the <bivalve> shell <curvature>/
       1. bent, with one margin quite sharply incurved and the other
          strongly curved outwardly/
       2. oblong, with the margin opposite the hinge more or less
          straight or only slightly incurved/
       3. not bent, the margin opposite the hinge outwardly curved/
 
#30. height <of the shell, relative to its width> about/
       x the width <shell height divided by width>/
 
#31. the shell <raised-spiral type, relative dominance of the body (=
          last) whorl>/
       1. with the body whorl predominating and the spire small and
          short/
       2. high-spired and tapered gradually from the body whorl/
 
#32. the height of the spire <relative to that of the shell> about/
       x that of the shell <height of spire divided by height of shell>/
 
#33. the spire <acute or obtuse>/
       1. acute/
       2. obtuse/
       3. truncate/
 
#34. the shell <symmetry>/
       1. more or less symmetrical about its vertical axis <implicit>/
       2. very asymmetric about the vertical axis, with the spire much
          displaced to one side/
 
#35. the shell <wider than or about as wide as high, shape>/
       1. discoid/
       2. conical <pyramidal, implying more or less straight-sided>/
       3. cochleate/
       4. subglobose/
       5. globose/
       6. very asymmetic about its vertical axis, with a large body <=
          last> whorl and a small, displaced spire/
 
#36. the shell <higher than wide: shape in outline, ignoring suturing of
          the spire>/
       1. cylindrical/
       2. fusiform/
       3. ovoid-symmetric/
       4. ovoid-asymmetric/
       5. inverted-pyriform <pear-shaped>/
       6. tear-shaped <cf. inverted-pyriform, but more gradually
          contracted into the spire>/
       7. turretiform <elongated-conical, implying more or less
          straight-sided>/
 
#37. the shell <whether deeply sutured>/
       1. shallowly sutured/
       2. deeply sutured/
 
#38. the body whorl <of the shell, convexity>/
       1. only slightly convex/
       2. moderately convex/
       3. very strongly convex/
 
#39. the whorls of the <elongated> spire <of the spired shell,
          convexity>/
       1. feebly convex/
       2. moderately convex/
       3. very strongly convex/
 
#40. the whorls <of the shell, outline in section>/
       1. neither shouldered nor keeled <implicit>/
       2. shouldered/
       3. keeled/
 
#41. the whorls <of the shell, whether spiny>/
       1. exhibiting a median whorl of spines/
       2. without spines <implicit>/
 
#42. the whorls <of the shell, whether transversely ridged>/
       1. conspicuously and regularly transversely ridged <as distinct
          from striated> across the whorls/
       2. not conspicuously transversely ridged <implicit>/
 
#43. the shell <elongate-spired, whether longitudinally striated>/
       1. conspicuously and regularly striated across the whorls <i.e.,
          along its length>/
       2. not markedly striated across the whorls <implicit>/
 
#44. the aperture <of the shell, shape>/
       1. round/
       2. oval/
       3. ovate/
       4. lunate <crescentic>/
       5. pear-shaped/
 
#45. the aperture <of the shell, teeth or calluses>/
       1. bearing teeth/
       2. bearing calluses/
       3. with neither teeth nor calluses/
 
#46. the columella <smooth, folded or twisted>/
       1. smooth/
       2. folded/
       3. twisted/
 
#47. the shell <presence of umbilicus>/
       1. with an umbilicus/
       2. without an umbilicus/
 
#48. the umbilicus <of the shell, size>/
       1. small/
       2. large and wide/
 
#49. the shell <aperture lip, thickening>/
       1. thick-lipped/
       2. thin-lipped/
 
#50. the shell <consistency>/
       1. thin and translucent/
       2. <relatively thick and> opaque/
 
#51. the shell <ground colour>/
 
#52. the shells <colour details,
          \i{}Margaritiferidae\i0{}/\i{}Unionidae\i0{}>/
       1. dull black, the interior pearly white or pinkish
          <\i{}Margaritiferidae\i0{}>/
       2. brown, bright or dark greenish or greenish brown, glossy
          <\i{}Unionidae\i0{}>/
 
#53. the shell <patterned or plain>/
       1. conspicuously colour-patterned/
       2. plain/
 
#54. <comments on body colour>/
 
#55. <terrestrial or aquatic>/
       1. terrestrial/
       2. freshwater aquatic/
       3. semi-marine <in saltmarshes and brackish water, or around the
          high tide zone>/
 
#56. <respiratory organization>/
       1. breathing via a single gill <ctenidium> attached within the
          mantle cavity/
       2. breathing air directly via the lung-like mantle cavity
          <without gills: implicit>/
       3. breathing via complex gills/
       4. the mantle cavity obliterated, and a lobe of the mantle
          functioning as a gill/
 
#57. <whether principally carnivorous>/
       1. principally carnivorous/
       2. not principally carnivorous <implicit>/
 
#58. lifestyle <whether subterranean>/
       1. subterranean/
       2. not subterranean <implicit>/
 
#59. <non-subterranean habitat, comments>/
 
#60. <comments on diet>/
 
#61. <sexuality>/
       1. hermaphrodite/
       2. the individuals either male or female (not hermaphrodite)/
 
#62. <viviparous or oviparous>/
       1. viviparous/
       2. oviparous <implicit>/
 
#63. the stalk of the bursa copulatrix <presence of a diverticulum>/
       1. with a diverticulum/
       2. without a diverticulum/
 
#64. courtship <whether involving love darts>/
       1. involving exchanges of love darts prior to mating/
       2. not involving love darts <implicit>/
 
#65. the darts <calcareous or chitinous>/
       1. calcareous/
       2. chitinous/
 
#66. <Class>/
       1. Gastropoda/
       2. Bivalvia/
 
#67. <Subclass of Gastropoda>/
       1. Prosobranchia/
       2. Pulmonata/
 
#68. <genera in Britain, numbers of species, and common names>/
 
#69. <general comments>/
 
#70. abbreviated taxon name:/
 
#71. <illustrations>/
