234 



Differs from G. striatus, Brod. (which must not be confounded 

 with Dispoteea striata, Say), in its much more delicate, irregular, 

 finely spinous striae ; and in the form of the internal laminae, which 

 in this species is reflected back over two-thirds, in G. striata over the 

 whole, forming a much larger umbilical region. The vertex of this 

 shell is rather prominent, and is formed like a tumid Planorbis, with 

 a sunken apex. 



19. FlSSTJRELLA NIGROCINCTA. 



F. t. ovali, lata, conica ; alba, lineis nigris radiantibus eleganter 

 picta ; striis radiantibus tenue ccslata ; apertura subcentrali, ob- 

 scure trilobata ; intus alba, margine tenue crenulato, denticulis 

 nigris; callositate alba, linea nigra cincta. 

 Long. "75, lat. '52, alt. "3, poll. 



Differs from the young of F. alba in its greater breadth, less com- 

 pressed growth, finer striae and crenulations ; from F. nigropunctata, 

 in the black line round the callosity ; and from both in the form of 

 the hole, which is trilobed, not contracted in the middle. 



20. Callopoma (Turbo) ? fluctuatum, var. depressum. 



C. t. valde depressa, anfractibus v., quorum ultimus tumidus, sutura 

 impressa ; liris spiralibus circiter xxx., quorum plerumque y. 

 majores sunt, subrugosis ; viridi, punctis albis trunsversim in liris 

 subirregulariter dispositis ; apertura ad basin posteriusque pro- 

 ducta; columella paulum excavata, non umbilicata. 

 Long. 2-02, lat. 2'04, long. spir. '78, poll.; div. 110°. 

 Hob. California. Mus. Cuming. 



Syn. Turbo fluctuatus, var., Rve. Conch. Ic. pi. viii. f. 34. 

 Among many hundred specimens examined of the true C fluctuatum 

 from the Mazatlan Collection, there was not one approaching this 

 shell. Nevertheless, as there is in the British Museum a somewhat 

 intermediate form, it may possibly be a variety of that species. The 

 operculum is unfortunately wanting in Mr. C.'s specimens : until that 

 has been examined, the point must remain in abeyance. 



21. Litiopa DIVISA. 



L. t. parva, anfractibus ix., quarum vi. primi subturriti, liris trans- 

 versis striisque spiralibus decussati, ultimique tres subl<eves sunt, 

 tumidiores, striulis plus minusve appressis, spiralibus, maxime ad 

 basin, tenuissime ornata ; nonnunquam linea suturam impressam 

 subeunte ; subdiaphana, fusca ; labro acuto ; labio vix monstrante; 

 columella truncata, infra maxime undata. 

 Long. - 13, lat. -06, long. spir. "07, poll. ; div. 30°. 

 Hab. Cape San Francisco : legit clar. Hinds. Mus. Cuming. 

 This is the only species hitherto recorded from the west coast of 

 N. America; the 1L. saxicola of C. B. Ad. not belonging to the 

 genus. Exactly the same species was taken in abundance " among 

 small drifted canes, Straits of Sunda," Mus. Archer. It is remark- 

 able for the different character of the first six and the last three 



