DALL : MOLLUSCA AND BRACHIOPODA. 341 



Cocculina nassa Dall, n. sp. 



Plate 16, ngures 3, 6. 



Shell small, white, "with a pale brownish periostracum, subquadrate, with the 

 apex subceutral, the anterior slope slightly convexly arched, the posterior slope 

 direct; apex eroded in all the specimens; sculpture of low, sharp, somewhat 

 irregular concentric laminae, which have their heiglit slightly increased by an 

 added film of periostracum, and are stronger on the upper part of the cone ; 

 beside these there are fine lines of growth ; the concentric sculpture is crossed by 

 subequal fine radial threads extending from the apex to the margin, with few orno 

 intercalaries ; the radial tlircads are not laminar like the concentric sculpture, and 

 near the apex are closer togetlier, but diverge as they approach the margin, which 

 is only crenulate by them in the adolescent stages ; tlie intersections are not 

 nodulous; interior polislied, bluish white, the muscular impressions hardly visible. 

 Length, 8.5; apex, 4.5 behind the anterior margin; breadth, 5.5 ; height, about 

 5.0 mm. 



U. S. S. "Albatross," station 3392, Gulf of Panama, in 1270 fathoms, hard 

 bottom, temperature 36°.4 F. U. S. N. Mus. 123,053. 



This species has the sharpest sculpture of any yet described. It is more ele- 

 vated and relatively less arcuate than the preceding species, while none of the 

 Atlantic species is so sharply reticulated. 



Cocculina diomedae Dall, n. sp. 



Plate 16, flgures 4, 7. 



Shell rather large for the genus, white with a pale straw-colored periostracum, 

 depressed conic, somewhat pai-allel sided, with rounded ends, apex nearly central, 

 eroded ; margin thin, sharp, entire ; interior bluish-white, polished, the muscular 

 impressions strong. Lon. of shell, about 13.0; height, 4.5; length of posterior 

 slope, CO ; width of shell, 8.5 mm. 



U. S. S. "Albatross," station 3393, Gulf of Panama, in 1020 fathoms, mud, 

 bottom temperature 3f)°.8 F. U. S. N. Mus. 123,052. 



This species in form and size closely resembles C. rathbuni of the Atlantic, but 

 on examination with a good lens the fine radial striation of the latter (which is not 

 represented on the figures of the species, being too fine for the enlargement) is 

 entirely absent, the periostracum is less continuous and not shining, and of a 

 greenish tint, while that of C. rathbuni inclines to brown. 



Turhinidae. 



TURBO LiNNE. 



Turbo saxosus Wood. 



A dead and broken specimen probably of this species was dredged near Cocos 

 Island, at station 33C8, in 06 fathoms, rocky bottom. U. S. N. Mus. 123,054. 



