PROCEEDINGS OF THE NATIONAL 



VOL. XX. 



776 



In order to avoid, so far as possible, the uncertainty necessarily 

 connected with mere descriptions of these forms, we have had large 

 cainera-lucida figures made, as carefully as possible, not only of the 

 new species, but also of some of those previously described from our 

 coast, for comparison. It is, therefore, to be hoped that future investi- 

 gators may at least be able to understand the characters of the species 

 now recognized by us, whether they agree with our determinations or 



not. 



Although the collections studied are unusually extensive, and the 

 number of stations represented is very large, it is noteworthy that a 

 considerable number of species were met with but once, and sometimes 

 only a single specimen was obtained. This indicates that many addi- 

 tional species of such small deep-sea shells would be discovered in the 

 same region if additional dredgings should be made. 



Our investigations have enabled us to add to the fauna nine genera, 

 four subgenera, and about eighty species and varieties, of which about 

 seventy are described as new species and seven as new varieties; of 

 these, twelve species and one variety belong to the southern fauna. 



The following list shows the genera in which the new species and 

 varieties are included. 1 The new genera are printed in italic: 



Poromya, var. 1. 

 Cetoconcha, 2. 

 Cetomya, 1. 

 Lyonsiella, 2. 

 Lyonsia, 1. 

 Clidiophora, 1. 

 Keunerlia, 1. 

 Periploma, 1. 

 Limatula, 3. 

 Chlamys, 2. 

 Hyalopecten, 1. 

 Cauiptonectes, 1. 

 Cyclopecteu, 2. 



Bathyarca, 2. 

 Ben tli area. 

 Limopsis, 2. 

 Soiemya, 1. 

 Nucula, 1, var. 1. 

 Leda, 1. 



Lrdella, 1, var. 1. 

 AdrantUa, 1. 

 Microyoldia. 

 Yoldiclla, 11, var. 1. 

 Malletin, 2. 

 Neilonella, 1. 

 Tindaria, 3. 



MartesieUa, 1. 

 Abra, var. 1. 

 Macoma, 1 

 Montacuta. 4, var. 2. 

 Kelliopsia. 



Cryptodon, 4, var. 1. 

 . I. i-i a itl us, 6. 

 Axiuopsis, 1, var. 1. 

 Ajcinodon, 1. 

 Lepta.riinis, 1. 

 Cuspidaria, 8. 

 Cardioinya, 2. 

 Halonyinpha, 1. 

 Myonera, 3. 



No attempt has been made to give the complete synonymy and 

 details of the distribution. Such matters have been reserved for the 

 final report on the collections. 



Unless otherwise stated, the station numbers are those of the 

 United States Fish Commission and the serial numbers are those of 

 the United States National Museum. 



The drawings, with few exceptions, were made by Mr. Alpheus H. 

 Verrill, under the immediate supervision of the authors. 



Peabody Museum of Yale University, New Haven, Connecticut, January 25, 1897. 



'Owing to the long delay iu the publication of this article, some of the new 

 species and genera have been published elsewhere, so that these numbers are not 

 now strictly correct. 



