THYSA. 141 



F. W. Shells, p. 127, f. 110. —Jeffreys, Trans. Linn. Soc. 

 vol. xvi. p. 379.— Gray, Manual L. and F. W. Shells, p. 251, 

 pi. 9, f. 110.— Macgil. Moll. Aberd. p. 1 12.— Brown, 111. 

 Conch. G. B. p. 30, pi. 14, f. 5455. — Brard, Coq. Paris, 

 p. 167, pi. 7, f. 7, 8. — Sturm. Deutsch. Fauna, sect. 6, pt. 4, 

 pi. 10. — C. Pfeif. Deutsch. Land und Slissw. Moll. pt. 1, 

 p. 94, pi. 4, f. 28. — Lam. Anim. s. Vert. (ed. Desh.) vol. viii. 

 p. 399. — Kickx, Moll. Brabant, p. 54. — Philippi, Moll. 

 Sicil. vol. ii. p. 120. — KtisT. Conch. Cab. i. sect. 17, pi. 2, 

 f. 14, 15, 16'. — Cantraine, Mem. Ac. Sc. Brux. vol. xiii. 

 p, 163. — Stein, Schnecken Berlins, pi. 2, f. 6. 



Helix Bullaoides, Donov. Brit. Shells, vol. v. pi. 168, f. 2, probably,* from which 

 Maton and Rack. Trans. Linn. Soc. vol. viii. p. 223. 



Bulla fulviatilis, Turt. Conch. Diction, p. 27. 



Limnea fontinalis, Sowerby, Genera Shells, Liin. f. 8. — Reeve, Conch. Syst. 

 vol.ii.pl. 192, f. 8. 



Shell oval or abbreviated oval, with a very short spire, 

 which only fills about a fifth of the dorsal length, tapers 

 quickly and convexly to its obtuse apex : more or less 

 transparent, extremely thin and fragile, highly polished, 

 smooth or nearly so (yet sometimes with rather strong 

 longitudinal wrinkles), and of a slightly and palely oliva- 

 ceous yellowish horn-colour, becoming pallid in the larger 

 examples. Whorls four to five, simply but decidedly 

 convex, neither angulated nor planulately shelving below 

 the fine suture, which becomes more slanting between 

 the last two turns ; superior volutions very short, of 

 moderately fast longitudinal increase ; body ventricose, its 

 basal declination moderately rounded, yet not abrupt. 

 Mouth lanceolate -subpyriform, capacious, filling almost 

 one-half of the ventral area, and from three-fourths to 

 four-fifths of the total length, dilated below, where it 

 projects anteriorly, gradually contracted above by the 

 swell of the body to a very acute curved peak. Outer 

 lip sharp, prominent, subarcuated, not expanded, nor mar- 



* The expression " ovate, spire short," modifies the ideal of the figure, which 

 exhibits a rather more elongated spire, and is narrower than is usual in fontinalis. 



