PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 403 



organ, if furnished with jaws at all, lias them of such soft and cuticular 

 consistency as to show neither under the knife nor under an ordinary 

 dissecting microscope, but it appeared to be without jaws; tentacles 

 moderate, subcylindrical ; eyes none ; course of the intestine much as 

 in Patella, but shorter. ^ — 



Dentition. — Ehachidian tooth squarish, rounded in frent, nearly flat, 

 about as long as the two inner laterals ; inner three laterals slender, 

 with small denticulate cusps, outer or third usually a little longei^than 

 the others, but the proportions slightly diflerent in the leiss mature part 

 of the radula; fourth or major lateral about twice as long as the others 

 and slightly broader than the rhachidian tooth, rather strongly cusped, 

 the cusp notched into five or six denticles, and the shaft somewhat 

 curv-ed, the shaft and cusp translucent; uuciui numerous (100 oi*more), 

 slender, slightly twisted and hooked, united on each side on a single 

 continuous base, which is a little longer than the width of the radula 

 between the uncini. 



Habitat. — Station 937 of the United States Fish Commission in 1881. 

 This is 102 miles S. by E. i E., by compass, from Gay Head Light, 

 Martha's Vineyard. The bottom temperature being 40'=^.o F., and that 

 of the surface 12^.0 F. The same s^iecies was obtained by the United 

 States Coast Survey dredgers on the steamer Blake, Lieutenant-Com- 

 mander J. E. Bartlett, commanding, under the supervision of Prof. 

 Alex. Agassiz, on hard bottom (temperature 440.5 F. ) , at station 288, in 399 

 fathoms, off Barbadoes ; and off Martinique, in 502.J fathoms sand and 

 ooze, at station 195, bottom temperature 41^.0 F., the surface in both 

 cases being about 80^.0 F. I take pleasure in naming this species after 

 Mr. E. Eathbun, of the United States Fish Commission. 



Cocculiua Beanii, u. s. 



Shell elevated, white, thin, resembling in sculpture and general fea- 

 tures the last species, except in the following particulars : The form of 

 the base is about as in C. Eathbuuiy but the profile differs widely, the 

 anterior and i^osterior slopes of the present species, instead of being 

 subequal and nearly similar, are unequal, the anterior being considerably 

 the longer, roundly and conspicuously arched ; the posterior slope is 

 about half as long as the other and deeply concavely excavated ; this 

 results from the fact that the apex, instead of being depressed and 

 nearly central, is elevated, subi)Osterior and much incurved ; like that of 

 the' previous species it bears a scar where the (probably spiral) embry- 

 onic shell was attached ; the sculpture resembles that of the preceding 

 species, being stronger and more cancellated in some specimens and 

 nearly obsolete in others. The very young show proportionally stronger 

 sculpture, even slightly spinous at the intersections in some specimens. 

 The surface is generally partly eroded, probably from the same action 

 as that Yv'hich so rapidly reduces dead shells and corals to a species of 

 gray ooze in the deep sea. There seems to be no indication of epidermis 

 m this species. Length 8.0; breadth 5.0; height 4.0'"°'. 



