PLATE I.— (Univalves). 



Fig. Spcdcs <i- Authority Colouring. 



1 Seementina nitida EecUlisIi horn 



(Mttlle.) colo 



2 Planorbis fontanus Pale lioin colon 



(Lightfoot) 



3 _ nautileus(Linn6) Greyish white 



4 — dilatatus (Gould) Horn eolouv 



5 — parvus (Say) .. Greyisli liorn cc 



6 - spirorbis(Miill.). Dark lioni colo. 



7 — albus (Miiller) White ... 



Chief Characteristics Habitat 



Nautilus-like, internal Ditches and slow 



septa visible outside streams 



Flatness, thinness, Ditches and |)oiids 

 sharp keel 



Small size, nautilus- Ditto 

 shape, ridges 



uth (in- Canals in Lanca- 



Expanded n 

 trod need) 



shin 



Marshes, ditclies, 

 absence of keel and ponds 



Faint keel, roundish Ditches, streams. 



Spiral striations 



Ditches, canals 

 and ponds 



— contortusd.inni') Dull lirowii, opaque Solidity, compactness. Ditches and ponds 



crescent-shaped mouth 



— vortex {Miin6) Pale horn colour Sharp keel, oval month Ditches, streams, 



etc. 



— umbilicatus Brown, nearly 



(iMiiller) opaqu 



corneus (LiuTie) Dark horn ( 



shells hispid 



FrerjHcnc)/ 



Local 



Frequent 



Frequent 



Rare 



Local 



Common 



Common 



Fiequent 



Comuion 



— carinatus 



(Midler). 



Yellowish horn 



Thinness, .^li.arp keel 

 ill centre of wh.ul 



Ditches 

 el.c. 



streams. 



Local 



Limnaea peregra 



(Miiller) 



Variable 



V^iiiation in shape and 



E<ery« 



here 



Abundau 



— var. burnetti 



Yellowish horn 



E.xtreniely short spire 



Loch SI 



ene, Duni 



Rare 



— var. acuminata 



Variable 



Produced spire 



Ditches 

 etc. 



ponds. 



F^reqnent 



— var. lutea 



Yellowish ho.n 



Solidity, short spire 



Near se 



vcoast 



Local 



— var. lacustris ... 



Ditto 



Transverse grooves, 

 glossiness, short spire 



Lakes i 



the north 



Frequent 



— var. obtusa 



Ditto 



Large size, expanded 

 mouth 



Ditches 

 etc. 



ponds. 



Local 



— var. oblong^a ... 



Ditto 



Oblong shape, com- 

 pressed in front 



Ditches 

 etc. 



streams. 



Local 



— var. ovata 



Variable 



whol-ls, oblong mouth 



Ditches 

 etc. 



ponds, 



Frequent 



Limnaea palustris 

 (-Miiller) 



Dull brown or 

 purplish 



Tapering spire, small- 

 isli mouth 



Ditches 

 ponds 



marshes, 

 etc. 



Common 



— auricularia 



Yellowish horn 



Very expanded mouth. 



Lakes, c 



aiials, and 



Frequent 



(Linn6) 



colo 



shorfc and ; 

 pointed spiie 



stag-nalis (Lining) Greyisli horn color Lar^e size, taperinji Canals, ponds, 

 spire rivers, etc. 



Varieties and /Monstrosities. 



PLATE I. 



' Segmentina nitida var. albina (■^a.^•lor) 

 Planorbis fontanus var. albida (Nelson) 

 _ nautileus var. laevigata (Adanii) 

 .- parvus var. compressa (Lloyd) 

 — spirorbis var. albida (.Jellreys) 

 _ — ■ ecarinata (.lell'reys) 



__ — albida (Nelson) 



m. scalariforme (N. & T. ) 



draparnaldi (Shepp.) 

 ir. sulcata (T.-udor) 

 I. scalariforme 



compressa (iMich.) 



While. 

 Wliit». 

 Without rid^ 

 More concave 

 Whitish. 

 No keel. 

 White. 



albus 



vortex 



corneus v: 

 carinatus i 



Limnaea peregra 



Whorls disunited. 

 Carinated, without spiral striae. 

 With strong curved cross ridges ami furrows. 

 Whorls twisted or disunited. 

 Thinner, flatter, more sharply keeled. 

 — umbilicatus var. rhombea (Turton) Smaller, more solid, more concave below. 

 . albina (Jeffreys) White, 



sinistrorsum (Taylor) Sinistral. 

 •. albina (Moq.) White, 



ir. disciformis (Jeffreys) Flatter and thinner. 



albida (Hudson) White. 



11. burnetti (Alder) CJlohose, rather solid, spire scarcely elevated, 



apex intorted- (Figured), 

 scalariforme (Jell'reys) Whorls disjointed, 

 sinistrorsum (Jeffreys) Sinistral, 

 decollatum (Jeffreys). Spire tiuncate. 

 r. acuminata (Jeffreys) Produced spire, smallish mouth. (Figured). 

 r. intermedia (l''erussac) Thin, compressed towards front margin, spire 

 produced, mouth expanded. 

 Very solid, short spire. (Figured). 

 Very thin and transparent. 

 Shell spirally baiuled brown and white 

 White. 



Shell having strong spiral ridges. 

 Outer lip expanded and reflected. 

 Shell small, glossy, with transverse grooves. 



(FiguiedJ. 

 Shell lar^'e, sjiiie small, whorls not very con- 

 vex, numtli pear shaped. 

 Sliell Large, spire short, whorls very convex, 



month ample. 

 Shell lar^e, spire small, month ample. (Figd.). 

 Oblong, compressed in front. (Figured). 

 Small, globose, whorls convex, spire produced. 

 Small, spire not very prominent, whorls and 



aperture less convex than type. 

 Small, lines of growth pronounced, slight 

 margin to aperture. 

 succineEeformis (Jeff.) Very thin, sliaped like a Succinea. 

 maritima (Jeffreys) Dwarfed, solid, spire produced, suture deep, 

 microstoma (Ivohelt) Long and slender spire, like L. palnstns. 

 ovata (Draparnaud) Shell large, rather thin, spire short, mouth 

 oblong. (Figured), 

 tagnaliformis (Taylor) Somewhat fusiform or spindle shaped. 



var. lutea (Montagu) 



vai-. diaphana (Parreyss 



var. picta (.lettVeys) 



var. Candida {I'urro) 



vai-. lineata (Bean) 



var. labiosa (Jeffreys) 



var. lacustris (Leach) 



var. inflata (Kobelt) 



var. patula (Da Costa) 



var. obtusa (Kobelt) 



var. oblong'a (Jeffreys) 



var. boissyi (Dupuy) 



var. vulgfaris (Pfeiffer) 



var. pulchella (Roftiien) 



