176 CERITHIOPSIS. 



crossed by three spiral riblets, the intersections minutely beaded, 

 body whorl with four spiral striae, besides a line below the periphery. 

 Length, 5 mill. 



Mediterranean, Atlantic. 



C. PROCERUM, Jeffreys. PI. 36, fig. 71. 



Solid, opaque, pale yellowish white, glossy ; whorls 13-14, some- 

 what convex, with curved, oblique longitudinal ribs, about 30 on 

 the last and 20 on the penultimate whorl, three uppermost whorls 

 nearly smooth, base marked with flexuous striae, in continuation of 

 the ribs, periphery of last whorl with a spiral ridge. 



Length, 10 mill. 



Between Scotland and Faroe Is* 



C. Danielseni, Friele, is a synonym. 



C. BIZONALIS, Jeffreys. PL 36> fig. 72. 



This is a fragment obtained by the Porcupine Expedition in the 

 North Atlantic O. It shows longitudinal distant riblets crossed by 

 two distant spiral riblets on each whorl. 



C. WHITEAVESII, Verrill. PL 36, fig. 73. 



Whorls angular, with longitudinal riblets, forming tubercles on 

 the angle, and an inferior row of tubercles just below the suture; the 

 body whorl has a spiral thread below the angle, with a smooth base. 



Length, 4 mill. 

 Off Martha's Vineyard, Mass. (365-500 fms.) ; Gulf of St. Lawrence 



(200 fms.). 



C. costulata, Whiteaves (not Moller), is a synonym. 



Section EUMETA, Morch, 1868. 



C. COSTULATA, Moller. PL 36, fig. 74. 



Shell solid, semitransparent, glossy, white, with sharp, prominent 

 longitudinal ribs, cut off at the periphery by a spiral ridge ; ribs 

 traversed and indented by two or three thread-like impressed lines 

 or striae, besides slighter, finer intermediate striae in the interstices of 

 the ribs and on the base. Length, 10 mill. 



Northern Europe Arctic America New England. 



It is Bittiwn arcticum, Morch, and C. Naiadis, Woodward. . 



Unfyured Species of Cerithiopsis. 



C. HANLEYANA, C. CONTIGUA, Monts. Mediterranean. 



C. CINGULATA, A. Ad. Japan. 



