MUSEUM OF COMPARATIVE ZOOLOGY. 183 



Nassarina Grayi Dall. 



Plate XXXII. Fig. 12 a. 



Shell solid, strong, yellowish white with darker brown spiral lines and about 

 six whorls. Nucleus smooth brown ; sculpture of numerous close-set spiral 

 threads, of which about every third or fourth is stronger and darker colored than 

 the others; transverse sculpture of stout ribs becoming obsolete behind the 

 periphery, thus giving the whorl a shouldered aspect, there are nine or ten of 

 these on the last whorl, extending well forward; the rib behind the aperture is 

 varicoid and swollen; the spiral sculpture passes over the ribs, which are a 

 little angulate at the periphery ; the whorl is. appressed to the suture, which in 

 the upper whorls is more or less waved by the ends of the ribs behind it; the 

 aperture is long, narrow, and somewhat contracted, the continuous margin less 

 elevated than in the preceding species; the base of the last whorl is somewhat 

 constricted, the canal is twisted, recurved, and with a strong siphonal fasciole; 

 the outer lip has about seven teeth of which the hinder ones are the stronger; 

 there is a rounded callus on the body and also a few denticulations on the 

 anterior part of the columella. Max. Ion. of shell, 12.0; of last whorl, 9.0; of 

 aperture, 6.0; max. lat. of shell, 5.8 mm. A larger but imperfect specimen is 

 15.5 mm. long. 



Habitat. Station 152, off St. Kitts in 122 fms., bottom temperature 67°. 5. 

 Stations 272 and 290, off Barbados, in 73-76 fms., coarse sand, bottom tempera- 

 ture 65° to 71° ; and U. S. Fish Commission Station 2354, in 130 fms., coral, 

 off the Arrowsmith Bank, Yucatan. 



This is a rather short broad species, and has a little the aspect of a Tritoni- 

 dea, but the pinched aperture suggests its reference to this group. 



Family NASSIML 



Genus NASSA Lamarck. 



The species of this genus are well known to be extremely variable, and a 

 large number of names have been applied to the varieties of the genus indige- 

 nous to the Antilles. 



With a large series of specimens it is less difficult to set specific bounds as 

 the varietal relations rapidly become evident. There may be a larger number 

 of species in the region, but all the specimens I have seen are referable to one 

 of six littoral or two deeper- water species of this genus. Curiously enough, of 

 this small number four have fallen into neglect of late years, and one appears 

 to be undescribed. N. trivittata does not appear to exist in a living state much 

 south of Cape Hatteras, and does not appear in the Antilles. The species which 

 occur are Nassa vibex Say,* N. acuta Say, N. consensu Ravenel, N. Hotessieri 



* N. unicincta Say will be referred to under Pkos. 



