88 BULLETIN 111^ UNITED STATES NATIONAL MUSEUM. 



There seems to be no question as to the identity of the National 

 Museum specimens with Watson's species as described from off Cule- 

 bra Island, West Indies, in 390 fathoms. 



In the museum collection are two lots: One specimen, Cat, No. 

 94294, U.S.N.M., collected by Commander Rush, United States Navy, 

 off Rebecca Shoals, Florida, in 430 fathoms, bottom of coral mud; 

 three specimens, Cat. No. 108163, U.S.N.M., dredged by the Albatross 

 at U. S. B. F. Station 2668, off Fernandina, Florida, in 294 fathoms, 

 bottom of sand and temperature 46.3° F. 



ENTALFNA QUADRATA, new species. 



Plate 15, fJRS. 2, 3, 6, 10. 



The shell is small, thin but solid, strongly curved, especially near 

 the apex. The tip is quadrate, the entire shell preserving a quadrate 

 section throughout; the flat surface of the convex side is the smallest, 

 that of the concave side the largest, and the two lateral spaces are 

 about equal. The color is hyaline white; translucent; the surface is 

 not brightly polished. In the tip portion the four flat spaces between 

 the angles are smooth but soon take on six to eight thread-like longi- 

 tudinal secondary riblets persisting to the end, the primaries remain- 

 ing always as definite corners or angles rather than ribs. No apical 

 features are present. 



The type, Cat. No. 95354, U.S.N.M., measures— length, 12 mm.; 

 diameter, 1.1 mm.; arc, 1.75; and was dredged by the Blalce at the 

 United States Coast Survey Station 248 off Grenada, in 159 fathoms, 

 bottom of fine gray ooze, temperature 53.5° F. 



The difference between this and Entalina platamodes seems well 

 defined in the few specimens at my command, but it is quite possible 

 that a series of many specimens would unite the two. 



Both this and E. 'platamodes are evidently species of the Antillean 

 island slope zone and probably occupy as well a still deeper range. 



Genus SIPHONODENTALIUM Sars, 1859. 



1859. Siphonodentalium Sars, Forh.Videnskabs-Selskabet i Christiania, Aar 1858, 

 p. 52. 



The shell is arcuate, slightly tapering, the largest diameter being 

 at the aperture; circular, or nearly so, in section; smooth, with a 

 rather large apex, which may be either simple or slit into lobes. 

 The foot of the animal is capable of expanding into a terminal disk. 



The subgenera indicated are : 



Siphonodentalium, characterized by the apex being slit into lobes 

 or teeth; and 



Pulsellum, which has a simple apex, unmodified by lobes or teeth. 



The genus includes a few species of cold water distribution, which, 

 for the most part, live upon the lower continental shelf or the ocean 

 floor. 



