254 BULLETIN OF THE 



It is entirely evident that this does not agree with the accounts given us 

 of the radula of C. tubercularis. On the other hand, Stimpson's drawing does 

 agree in the main with the dentition of Eumeta costulata Moller (C. arctica 

 Mdrch) as figured by Sars (Moll. Arct. Nov., pi. vii. fig. 5 b). The details 

 differ, but the main features of the radulae must be much alike. 



In the absence of better data as to the teeth of C. tubercularis, I prefer to let 

 the species remain in the genus, merely calling attention to the fact that this 

 species must be removed from Cerithiopsis, and united with its congeners in a 

 distinct group, if the differences of dentition above signalized are confirmed. 



Section CERITHIOPSIS s. s. 

 Cerithiopsis crystallina Dall. 



Plate XX. Flff. 3. 



Cerithiopsis 1 crystallina Dall, Bull. M. C. Z., IX. p. 89, 1881. 



Habitat. West of Florida in 50 fms. ; off Havana in 450 fms., Sigsbee ; 

 Barbados, in 100-103 fms. ; Station 2, in 805 fms. ; Station 20, off Bahia Honda, 

 in 220 fms.; Station 36, in 84 fms. ; Station 128, near Santa Cruz, in 180 fms., 

 sand; Stations 132 and 134, off Frederikstadt, Santa Cruz, in 115-248 fms., 

 sand; Station 176, off Dominica, in 391 fms.; Station 192, off Dominica, in 

 138 fms.; Station 210, near Martinique, in 191 fms.; Station 220, off Santa 

 Lucia, in 116 fms., rocky bottom; Station 290, near Barbados, in 73 fms., 

 coral. Bottom temperatures ranging from 43°.5 to 71°.0 F. Gulf of Mexico, 

 Stations 2400 and 2403; south of Cuba, at Stations 2131 and 2135; Little 

 Bahama Bank, at Station 2655, in 88-250 fms., U. S. Fish Commission. Cedar 

 Keys, Florida, washed on the beach, dead, Hemphill. 



This very abundant shell is remarkably uniform in its characters; the only 

 difference I have observed in examining several hundred specimens, from dif- 

 ferent places, is that some are a little more slender and cylindrical than others. 

 The tip of the larval nucleus is invariably lost, though a good part of the 

 larval shell is usually preserved 



The animal is pale brown (in alcohol), with large long tentacles, very black 

 well developed eyes, a broad short head, short rounded foot, and an externally 

 concave, red-brown, few-whorled circular operculum. The opercular lobe 

 appears to have several short processes on each side. 



Cerithiopsis Sigsoeana Dall. 



Plate XX. Fig. 1. 

 Cerithiopsis 1 Sigsbeana Dall, Bull. M. C. Z , IX. p. 87, 1881. 



Habitat. Station 5, 229 fms. ; Station 20, 220 fms. 



This is nearest C. Martensii, but the whorls do not overhang, and the arched 

 lamellae or incremental lines so prominent on the latter have no parallel in 



