302 SHELLS AND SHELL-FISH. PART II. 



typically of great length ; base truncated, deeply notched; 

 inner lip smooth, convex. 



Leiodomus Sw. Shell very smooth, nearly polished ; 

 spire acute, slender, lengthened; of few whorls; 

 aperture effuse; inner lip thickened and spreading; 

 base of the pillar curving inwards. 8 species. 



Achatinum. En. M. 400. f.4. Quoyii^w;. Voy. d'Astrol. 

 vittata. En. Meth. 402. f. 4. 31. f. 17. 



Terebba Lam.* Shell subulate; spire excessively 

 long, and of numerous whorls ; pillar straight ; the 

 base curving outwards {Jig. 71. e). 

 maculata. En. M. 402. f. 4. Babylonica. lb. 402. f. 5. 



BucciNvisi Linn. Shell pyriform ; spine moderate; body- 

 whorl ventricose ; base obtuse, emarginate ; hps 

 smooth {fig. 11. c). 



undatum. En. M. 399. f. 1. lineatum. lb. 400. f. 8. 

 ? leevigatum. lb. 400. f. 1 . t papillosum. lb. 400. f. 2. 



Trochia Sw. Shape intermediate between Purpura 

 and Bucciniim ; whorls separated by a deep groove ; 

 inner lip, when young, depressed, when adult, thick- 

 ened, convex, and striated ; basal canal very small, 

 sulcata. En. M^th. 422. f. 4. 



Tritonidea X Sw. Shell bucciniform, but the basal half 

 is narrowed, and the middle more or less ventricose ; 

 spire and aperture equal. Pillar at the base with 

 two or three obtuse and very transverse plaits, not 

 well defined ; outer lip internally crenated, and with 



* By this group, the Muricid^ are connected with the Strombid^ by 

 means of the Ccriiliince. 



t Probably an aberrant species of Leiodomus. 



% Mr. Gray has the merit of first publishing this intricate, but most natu- 

 ral genus, which I had many years ago also determined. 1 should gladly 

 have adopted his name, were it not that Pollia has been already given by 

 Hiihner and Trcitsch to a genus of lepidopterous insects. Mr. Gray has very 

 happily determined what is certainly its true station in the natural system, 

 — that is, intermediate between Triton and Biiccinmn. It is connected to 

 rritun by T. clandcsfinum. Ency. Meth. 433. fig. 1. [Jig. C4. p. 297.), which 

 thus completes the circle of this family. 



