A. E. Yerrill — Mollusca of the New England Coast. 263 



The form is pretty regularly elliptical. The apex is situated near 

 the posterior margin, prominent, acute, and directed strongly back- 

 ward ; it consists of rather more than one small coil, which is 

 regularly incurved and not distinctly turned to one side. The 

 internal septum is narrow and transverse. 



Although not agreeing exactly with either of Jeffreys' species, I 

 refer it doubtfully to P. pertenue. 



List of Deep-xoater and Surface Mollusca tahen off the East Coast of 

 the United States by the U. S. Fish Commission steatuers, Fish 

 Haxok and Albatross, 1880 to 1888. 



The following list includes all the species hitherto dredged along 

 the Gulf St7*eam slope, from off" Cape Hatteras to Nova Scotia, 

 except a small number of minute species, not yet fully identified. 

 In general, those species that have not occurred below 60 fathoms 

 are omitted. But the surface species of Heteropoda, Pteropoda, etc., 

 belonging to the Gulf Stream region, are included, whether taken 

 living at the surface or dead from the bottom. 



The " Bathymetrical range " refers only to the range as actually 

 observed in this region by the Fish Commission, unless otherwise 

 stated. The geographical distribution is indicated, in a general 

 way, by the abbreviations following the range in depth, but it is not 

 intended to be complete in this respect. Owing to the uncertainty 

 in respect to the alleged identity of the species recorded from other 

 regions with our own, and to the incompleteness of the published 

 lists of species collected by various recent dredging expeditions, 

 the knowledge of the foreign distribution of many of these species 

 is still very imperfect and sure to be largely increased within a few 

 years, so that any facts of this kind that can now be given will have, 

 at best, only a temporary value. The abbreviations are as follows : 

 N. =. northern, indicates that the species ranges northward along 

 the American coast, beyond New England waters; S., = southern, 

 southward beyond Cape Hatteras; Arc, = Arctic; Eu., =European; 

 Med., =Mediterranean ; Af., =West African; P., r=North Pacific; 

 As., =North Asia; Cb., ^Caribbean Sea and West Indies; Oc, = 

 Oceanic or pelagic. 



After the names, references are given to the pages and plates 

 where the species are described or figured in this volume (vi) or the 



