66 PALUDINID^. 



sex. British authors have referred this species to the 

 Cyclostoma anatinum of Draparnaud, but_, as I believe, 

 erroneously. The Bulimus anatinus of Poiret, from which 

 Draparnaud seems to have taken the specific name of 

 his species, is in all probability the Turbo ulvce of Pennant. 

 That species is universally known in France by the name 

 which Poiret gave. Michaud, in his Supplement to 

 Draparnaud's last work, mentions Cyclostoma anatinum 

 as inhabiting " les eaux saumatres ; ^^ although Drapar- 

 naud gives a difPerent habitat (" les eaux donees") for the 

 same species. It is not impossible that the latter meant 

 Bythinia Leachii. The contour of the shell of H. similis 

 is not unlike that of a dwarf Bythinia Leachii ; but the 

 channeled suture, as well as the very different operculum, 

 will readily serve to distinguish them, irrespectively of 

 size. 



2. H. VENTRo'sA *, Montagu. 



Turbo ventrosus, Mont. Test. Brit. ii. p. 317, pi. 12. f. 13. Rissoa vetiirosa, 

 F. & H. iii. p. 138, pi. Ixxsvii. 11,5, 6, 7. 



Body dark grey, almost black in front: head rather pro- 

 tuberant: snout long and ridged transversely: tentacles fili- 

 form, with black and grey rings : eyes on very short stalks, 

 placed a httle behind the outer base of the tentacles : foot 

 cleft in front and rounded behind. 



Shell forming a lengthened cone, rather thin, glossy, semi- 

 transparent, yellowish horn-colour, obscurely but closely 

 striate by the lines of growth : epidermis very delicate : luhorls 

 6-7, rounded and swollen ; the last not being equal to half 

 the length of the shell : spire pointed : suture rather obhque 

 and deep : mouth oval : outer lip thin, shghtly reflected : inner 

 lip in adult specimens separate from the columella and forming 

 with the other lip a complete peristome : umhilical chink very 

 small : operculum like that of II. similis, but having a smaller 

 spire and closer lines of increase. L. 0*2. B. 0-125. 



* Swollen. 



