98 VOLUTELLA, PSEPH^EA. 



dimension given above. Although the habitat of the species is 

 not known, it is very probably Patagonia. 



Y. BRASILIANA, Solander. PL 29, figs. 113, 115, 111; PL 30, 

 fig. 131. 



Yentricose, with depressed conical spire ; brownish yellow, 

 without markings. Length, 4-6 inches. 



So. America, from mouth of Rio de la Plata to Patagonia. 



V. Ferussaci, Donovan (fig. 131), is almost certainly a worn 

 specimen of this species. I have a shell before me, precisely 

 the same shape, but with the tubercles slightly indicated on the 

 shoulder. F. rudis, Gray (fig. Ill), is usually considered a 

 synonym of Ferussaci ; Gray's figure represents a shell in very 

 bad condition. The specimen figured in the Thesaurus corre- 

 sponds so little with the description as to indicate a very vivid 

 imagination on the part of the colorist of that work. 



Sect. 9. Volutella, d'Orbigny. 



Shell smooth, subcylindrical, with angulated whorls ; spire 

 acuminated, polished, and entirely covered by an enamel deposit, 

 obliterating the suture-line more or less entirely ; columella with 

 three oblique plaits ; lip sharp, not reflected. The development 

 of a lobe of the mantle to cover the spire is a peculiarity in this 

 animal not shared by the other species of the genus. 



Y. ANGULATA, Swainson. PL 29, figs. 112, 121. 



Pale yellowish ; with longitudinal irregular chestnut lines. 



Length, 4-6 inches. 



Mouth of Rio de la Plata to Patagonia. 



The enamel deposit frequently projects above the spire into a 

 beak (fig. 112), but is usually broken off in cabinet specimens. 



Sect 10. Psephaea, 



Shell oblong-fusiform, very finely transversely striated and 

 i'u i'n islud with longitudinal ribs, disappearing towards the 

 middle of the last whorl. Nucleus ? Columella furnished with 

 two principal plicae, above which there' are two or three minute 

 ones hardly visible; it presents also this peculiarity (in the 

 adult shell), that these plicae are situated so far within as to be 

 invisible when the shell is placed right in face of the observer. 





