VASUM. 7 1 



Domingo, and the West Indies is given as habitat in the " Con- 

 chylien Cabinet," but the species does not occur in the Swift 

 Collection, and I think there is no other authority for this 

 locality. The young shell is so covered with nodules and revolv- 

 ing ribs as to be readily mistaken for another species. The 

 revolving sculpture disappears and the nodules become fewer 

 and more prominent with advancing age. This and the next 

 species do not fall completely within the generic characters of 

 Turbinella; the sculpture and nodules indicate a transition to 

 Vasum, but they have not the elaborate ornamentation of the 

 latter genus particularly its spiriose fasciole. 



T. FUSUS, Sowb. PI. 20, fig. 9. 



White, covered with a thick, fibrous epidermis tufted in rows. 



Length, 7 inches. 



Habitat unknown. 



The tufting occurs upon the distant revolving riblets. It is 

 possible that this is a specimen of T. scolymus, in which the 

 development of the tubercles has been partially arrested. 



Genus VASUM, Bolten. 



V. MURIATICUM, Born. PL 20, figs. 10, 11 ; PL 21, fig. 10. 



White, covered with a rather thick, fibrous brown epidermis ; 

 coluinella tinged with rose-color. Length, 3'5-5'5 inches. 



Went Indies ; Panama; Mazatlan. 



Reeve attempts to distinguish V. caestus, Brod. (fig. 12), from 

 the Bay of Caraccas, by its having broader furrows, larger 

 tubercles and only four instead of five plaits on the coluinella, 

 but these characters vary considerably in the numerous speci- 

 mens before me. The fifth plait is merely an incipient one 

 which sometimes occurs between the normal upper plait and the 

 next one below it. The West Coast specimens which I have 

 examined are all four-plaited, and this corresponds with Carpen- 

 ter's remark upon them in his "Mazatlan Catalogue." I think 

 that T. Crosseana, Souv. (fig. 19), described from a single 

 specimen, the localit}^ of which was doubtful, is probably only a 

 worn individual of this species. 



Y. RHINOCEROS, Gmelin. PL 21, figs. 13, 14. 



Variegated, whitish and chestnut - brown ; columella and 



