REPORT ON THE GASTEROPODA. 613 



rather transversely to the axis of the shell, and is separated from the body by a broad 

 shelf, in which is sunk a deep furrow interrupted at either end, for it is crossed to the 

 right by the outer lip running on from the mouth-corner to join the body -whorl, and to 

 the left it is crossed by a narrow rounded swelling from the axis. Outer Up bluntly 

 rounded on the edge, which projects freely all round the mouth with a slight opercular 

 ledge a little way within ; it is not patulous, but on the contrary is rather slightly con- 

 tracted ; the direction of the outer lip, from its insertion, is at first straight forward and 

 outward ; it then curves freely all round to its junction with the inner lip. Inner Up long, 

 very oblique, almost straight, having only a little bend at either end ; it is blunt, but hardly 

 thick ; behind it, and separating it from the body, is a strange, deep, wide, very oblique 

 furrow, from the middle of which opens an almost hidden poriform umbilicus. H. 0'064 

 in. B. 0-043. Mouth, height 0-021, to insertion of outer lip, 0"027 ; breadth 0"022. 



This curious species has obvious connections with Rissoa scrobiculata, Wats., but is very obviously 

 different in shape, colour, and in the details of the slightly similar mouth. The stippled lines of 

 the embryonic apex are more exquisitely delicate here than in that other. I had thought of sug- 

 gesting for these very singular Australian forms a genus Scrobs, but think it better to class them as 

 I have done. Both have manifestly relations with Rissoa glabrata (v. Miihlf.). 



2. Hydrobia, Hartmann, 1821. 



Hydrobia caliginosa (Gould). 



Litorina caliginosa, Gould, U.S. Expl. Exped., 1852, p. 198, pi. xiv. fig. 240. 



Hydrobia caliginosa, E. A. Smith, PhiL Trans, vol. 168, 1879, p. 7 (separate impression), pi. ix. fig. 8. 

 „ „ Studer, Fauna Kerguelensland, Archiv Naturgesch., 35th Year., vol. i. p. 129, 



No. 32. 



January 19-20, 1874. Royal Sound, Kerguelen. Shore. 



Habitat. — Tierra del Fuego (Gould) ; Kerguelen (E. A. Smith and Studer). 



In this species the epidermis is very thick and strong, while the shell is peculiarly weak. 



3. Eatoniella, Dall, 1876. 



Mr Dall published this genus in 1876 (Bull. U.S. Nat. Hist. Mus., vol. iii. p. 42), but Mr E. A. 

 Smith had described it the year before Mr Dall (Ann. and Mag. Nat. Hist., 1875, ser. 4, vol. xvi. p. 70), 

 under the name Eatonia, which, however, being preoccupied, gives place, as Mr Smith has recorded, 

 to Mr DaU's. In regard to the operculum which is the feature of distinction between this genus 

 and that of Rissoa, Mr Smith, remarking on Mr Gwyn Jeffreys' description of the similar operculum 

 in Jeffrey sia, says that the ossicle in Eatoniella is directed towards the inner margin, while in 

 Jeffreysia, as he understands Mr Gwyn Jeffreys' description (and that in opposition to his figure), 

 the ossicle proceeds from the outer margin. The misunderstanding, however, vanishes if it be observed 



