Z BULLETIN OF THE 



inhabit the region above defined, at any depth. Especial attention has 

 been paid to an enumeration of the valid species of our southern coasts, 

 so neglected for the last quarter of a century. But in families or gen- 

 era comprising a large multitude of species, such as the Pleurotomidae, 

 this has been impracticable, and has not been attempted. 



The Systematic List which precedes the text, while it enumerates 

 those species which are new, newly named, or treated of at length, 

 whether of the Blake Collection or merely illustrative of it, does not 

 include the numerous other species which are only incidentally referred 

 to or enumerated in generic summaries of the southern fauna. 



The present paper includes a systematic description and account of 

 the Gastropods* and Scaphopods comprised in the Blake Collection, 

 (excepting pelagic species which float on the surface,) illustrated by 

 data drawn from the collections of the U. S. Fish Commission made 

 south of Cape Hatteras. In the course of this account the nomencla- 

 ture has been discussed and rectified in several cases. In other cases 

 the generic names and arrangements commonly in use have been 

 adopted as they are found in the text-books, for want of time and mate- 

 rial to revise the ordinary classification if necessary. Anatomical de- 

 tails have been supplied whenever the material was available and the 

 interest of the subject seemed to warrant it. These details will be 

 found, as in Part I, under the heads of the respective genera and spe- 

 cies. They are too numerous to particularize. Perhaps those of most 

 general interest relate to the soft parts of Pleurotomaria, of the Volutidce 

 of the Gulf of Mexico, of Pedicularia, of certain forms connected with 

 Cerithiopsis, and of the various Limpets. The writer has been handi- 

 capped by the impossibility of getting an artist competent to make 

 suitable drawings from the magnified camera lucida sketches of anat- 

 omy, dentition, etc., and has been obliged to leave unillustrated many 

 of the points which he has described at length in the text. It has been 

 impossible, with his official engagements, for him personally to elabo- 

 rate these drawings. To Dr. J. C. McConnell he has been indebted for 

 admirable renderings of the shells, as heretofore. 



In addition to the acknowledgments made in Part T, the writer de- 

 sires to .express his indebtedness to the great quarto report on the 

 Gastropoda of the Challenger Expedition, by the Rev. Robert Boog- 

 Watson ; to the admirable Manual by Dr. Paul Fischer, recently con- 

 cluded ; and to the Manual which Mr. George W. Tryon, of Philadelphia, 



* The few Nudibranchs collected have been referred to Dr. R. Bergh, who will 

 report upon them separately. 



