MAZATLAN UNIVALVES 361 
A4i7. Hyprosia ULVz, Penn. 
Turbo ulve, ? Penn. Br. Zool. vol. iv. p. 1382.— Mont. Test. Brit. 
vol. ii. p. 318.— Forbes §& Hant. Br. Moll. vol. iii. p. 141. 
Paludinella stagnalis, (Linn.) Midd. Sib. Reise p.129.—? = Helix 
stagnalis (prima) Linn. Syst. Nat. no. 1248 :— Hanl. Ips. Linn. 
Conch. p. 380. 
Hydrobia ulve, H. & A. Ad. Gen. i. pl. 35, f. 10, 10a, 3, c. 
As the Mazatlan shells, after careful microscopic examin- 
ation, do not offer the slightest specific difference from the 
British specimens, it did not seem allowable, merely for geo- 
graphical reasons, to impose upon them anew name. Whether 
it be the first H. stagnalis of Zinn. as Middendorf supposes, is 
a matter of doubt; v. Hanl. loc. cit. The well known name 
of the English writers is therefore chosen; and for the syn- 
onyms, the Br. Moll. and Midd. Sib. Reise may be consulted. 
The Mazatlan specimens were small, measuring long. ‘1, 
lat. 058. 
Hab.— European seas, in brackish water, passim.— Caspian 
Sea, Hichwald.—Massachusetts and New York, teste Mid- 
dendorff.—South Coast of Okotsk Sea, on Alge, Midden- 
dorff-—Mazatlan ; 4 sp. in shell washings ;—L’pool Col. 
Tablet 1714 contains the smallest and the largest specimens. 
418, ? Hypropia ————, sp. ind. 
Tablet 1715 contains a shell resembling H. ulve, but with 
the apex more prominent, the whirls more swollen, and a spiral 
raised band running round a fairly developed umbilicus. It 
has four whirls, and measures long. °036, long. spir. ‘016, 
lat. °028, div. 50°. 
Hab.—Mazatlan ; 1 sp. off Chama; L’pool Col. 
Famizy JEFFREYSIADA, 
Genus JEFFREYSIA, Alder. 
Forbes & Hanl. Br. Moll. vol. iii. p. 151, 1850:—An. & Mag. 
Nat. Hist.1851, vol. vii. pp. 193, 460.— Woodw. Man. i. 137.— 
Phil. Handb. Conch. p. 172. 
Rissoella, Gray (sine diagn.) Proc. Zool. Soc. 1847, p. 159, 
no. 286 :—Fig. Moll. An. 1850, p. 86.—Phil. Handb. Conch. 
p. 195.—H. & A. Ad. Gen. vol. i. p. 325. 
Oct. 1856. hh 
