PLATE XLYI. 
1, 2. Lymnsea Pyramidalis. (Pyramidal Lymncea.) Elongated, sub-cylindrical ; body large, spire pyramidal, small, with five 
inflated volutions; aperture oblong; outer lip sharp, expanded; callus on columella. 
3,4. L. Maxima. (Great Lymncea.) Oblong-ovate; sub-cylindrical; body large, inflated; spire pyramidal, with five convex 
volutions ; apex obtuse ; aperture oblong; outer lip thin ; columellar lip reflected. 
5,6,7. L. Minima. (Least Lymncea.) Oblong-oval, convex, smooth; body large; spire small, with four inflated volutions; 
apex acute ; aperture elongated, contracted. Length, i in. 
8,9. L. Longiseata. (Lengthened Lymncea.) Elongated, smooth, shining; body large; spire, with six or seven inflated 
volutions ; apex acute ; aperture ovate ; outer lip thin ; pillar lip broad, with shallow, twisted plait. 
10,11. L. Fusiformis. (Spindle-shaped Lymnma.) Subfusiform, smooth, shining; body large, inflated ; spire small, pyramida 
with five volutions ; aperture elongated ; with sharp, regular lines of growth. 
12,13. Planorbis Obtusus. (Obtuse Planorbis.) Depressed, discoidal, smooth, pellucid, shining; volutions few, greatly con¬ 
cealed ; aperture oblique, obtuse, sub-cordiform. 
14,15. Vermetus Striatus. (Striated Vermetus.) V. PLATE XLIIL, figs. 14, 15. 
16,17. L. Columellaris. (Columellar Lymncea.) Oblong-ovate, smooth; body large ; spire short, with four volutions; aperture 
oblong, wide; outer lip thin, ample; inner lip, with broad, twisted, thick columella. 
18,19,20. P. Hsemestoma. ( Bed-mouthed Planorbis.) Discoidal, depressed, smooth; spire convex, umbilicate; base flat; 
aperture sub-triangular, oblique. Diameter, ^ in.; thickness, in. 
21,22. P. Cylindrieus. (Cylindrical Planorbis.) Cylindrical; with three or four volutions; with concentric strhe on left side ; 
aperture transverse, oblong, quadrangular. 
23,24. P. Euomphalus. (Euomphalns-formed Planorbis.) Discoidal; with five or six volutions, sub-carinated ; with concentric 
striae; upper side flat; under side rounded, umbilicate; aperture sub-triangular. 
25. Crassidorsa Equalis. (Equal-sided Crassidorsa.) Smooth, concave; with single keel on right side, and two on left ; with 
five rounded volutions; aperture orbicular; with concentric striae. 
26, 27. P. Lens. (Lens-shaped Planorbis.) Lenticular, flat; concave above and below', sub-carinated; aperture sub-cordate, 
oblique. 
28. Auricula Sedgwickii. (Sedgwick's Auricula.) Ovate; body large; spire small, w'ith three volutions ; apex obtuse; aperture 
oval; one plait on pillar lip. 
29. A. Obsoleta. (Obsolete Auricula.) Sub-orbicular; body large; spire small, with two volutions ; with series of many spiral 
punctuated striae. 
30,31. Bulimus Costellatus. (Ribbed Bulimus.) Oblong-ovate, inflated; spire, with four volutions; apex obtuse; aperture, 
elongated, acute above; with many small, longitudinal, oblique ribs. 
32, 33. A. Pyramidalis. (Pyramidal AuHcula.) Ovate, smooth; bod}' large; spire small, pyramidal, with five or six volutions; 
apex acute ; aperture elongated ; outer lip sharp ; inner lip thickened, with two plaits on columella ; umbilicus behind. 
34, 35. A. Ventricosa. (Ventricose Auricula.) Sub-ovate; body large, inflated; spire conical, with four volutions; apex acute; 
aperture elongated, contracted ; outer lip thickened, reflected; inner lip, with broad, thick, callous plait and three sharp plaits ; base 
notched ; with regular, spiral striae. Length, £ in. 
36, 37. B. Ellipticus. (Elliptical Bulimus.) Elongated ellipsis; spire, with five reversed, inflated volutions; apex obtuse; 
aperture small, narrow' ; columella oblique ; outer lip plain ; with many longitudiual, oblique ribs, with sulci between; Length 
sometimes 4 in. 
38,39. A. Bueeinea. (Buccinum Auricula.) Subovate, smooth; body ventricose; spire, with four volutions; apex acute; 
aperture elongated, narrow; outer lip thickened ; inner lip, with broad reflection, and three strong plaits; base notched. Length, jj- lU * 
40,41. A. Simulata. (Dissembled Auricula.) Oblong-ovate; spire, with four ventricose volutions; aperture elongated; outer 
lip sharp, striated internally; columellar lip thickened, w'ith two broad plaits ; with spiral, close-set, serrated ribs. Length, { in. 
42,43. A. Discrepans. (Discrepant Auricula.) Oblong-ovate; spire conical, with five ventricose volutions; apex acute, 
aperture oblong ; outer lip plain, sharp, internally striate; pillar lip reflected on columella, with three oblique plaits ; with spitnh 
serrated ribs. 
44,45. A. Incrassata. (Thickened Auricula.) Ovate, ventricose; body large; spire small, with three volutions; apertui e 
smooth, oblong, semi-lunar; outer lip broad, thickened, with longitudinal lines of growth, instead of sulci, reflected ; pillar lip broad, 
thick, with three plaits ; with many spiral ribs, with sulci with sharp, w'ider-set stria3. 
46,47. A. Turgida. (Swollen Auricula.) Sub-ovate, glossy; body large, orbicular; spire short, with three volutions; a P c * 
acute; aperture oblong; outer lip thick, smooth internally; inner lip reflected on columella, with tw r o, thin folds ; with fine, reguh ll > 
spiral strim. Length more than -J in. 
( 53 ) 
