178 BULLETIN OF THE 



the shelL The oblique basal fold of the columella, regarded as characteristic 

 by Mr. Tryon, can be observed in nearly every species of Nassa which one may 

 examine, and is, in fact, conspicuous. 



But a very small amount of investigation in this case, as in many others, will 

 show that, apart from the bare shells, there is much yet to be learned about 

 almost all these animals. 



Phos ? unicinctus Sat. 



Nassa unicincta Say, Journ. Acad. Nat. Sci. Phil., V. p. 211, 182G; Tryon, Mar. 



Conch., p. 35, fig. 55. 

 Nassa guadeloupensis Petit, Journ. de Conchyl., IIL p. 56, pi. ii. figs. 3, 4, 1852 



krebs. Cat., p. 32 ; Beau, Cat., p. 11. 

 Nassa textilina Mbrch,Jide Tryon, Man., p. 220. 

 Phos guadeloupensis Arango, Fauna Mai. Cubana, p. 201, 1878; Tryon, Man., III. p. 



219, pi. ixxxiii. figs. 512, 520. 



Habitat. St. Thomas, C. B. Adams. St. Croix, Rawson. Shore at Curagao, 

 U. S. Fish Commission. 



The South Carolinian habitat assigned by Say was doubtless accidental or 

 erroneous. This shell has more the aspect of a Nassa than of a Phos, as these 

 go, though considerably resembling the specifically distinct Phos pallidus of 

 the west coast of America. But it has the operculum neither of a Nassa nor of 

 a Phos ! The operculum is lozenge-shaped, pointed in front and behind, with 

 a nearly central nucleus and concentric elements much like those of Buccinum 

 except in outline. In our present ignorance as to the character of the opercu- 

 lum in nearly all the species of Nassa and most of the species of Phos, I do not 

 think it advisable to propose a new sectional name for this form, as it may very 

 probably turn out to be characteristic of some of the sections of Nassa already 

 named on conchological grounds. 



Phos Beaui Fischer & Bernardi. 



Phos Beaui F. & B., Journ. de Conchyl., V. p. 358, pi. xii. figs. 8, 9, 1860 ; Krebs, 

 Cat., p. 32 ; Fischer, Cat. Beau, p. 10. 



Habitat. Barbados, in 73-82 fms., at Stations 272, 290, and 293, bottom 

 temperature 65° to 71° F. 



The soft parts of this species are white, dotted with blackish toward the 

 middle line of the foot above, and with the end of the siphon very dark brown. 

 The eyes are very large in proportion to the size of the animal, are mounted 

 on large long stout peduncles, from the inner side of the distal end of which pro- 

 ceed very slender acute tentacles. The foot is large, thin, with an entire edge 

 and pointed linguiform tail-end. In withdrawing it into the shell it is doubled 

 transversely in the middle. The operculum is like that of Phos as figured by 

 H. & A. Adams. When entirely perfect the point terminates in a little claw- 

 shaped process. The surface of the body is smooth and without accessory fila- 



