A. EF. Verrili— Mollusca of the New England Coast. 289 
The different groups of mollusea differ greatly in the relative pro- 
portion of deep and shallow-water species, as shown by the following 
tables. Thus the deep-water Cephalopods are 23, against 4 shallow- 
water and surface species. The Gastropods exclusively deep-water 
- are 166, against 38 of shallow-water origin. The shallow-water La- 
mellibranchs, however, seem to have a much greater tendency to 
range into deep-water, for of these there are but 68 deep-water species, 
associated with 46 shallow-water ones. 
The species and varieties described as new, in this paper, are 72, as 
follows: Cephalopoda, 4; Gastropoda, 56; Solenoconcha, 3; Lamel- 
libranchiata, 9. The total number of species of mollusca added to 
the fauna of ‘this region by the Fish Commission dredgings, since 
1880, is about 300, but only 276 of these are included in the above 
list; of these 121 were obtained in 1883. 
Among the peculiarities of the deep-water mollusca the occurrence 
of an unusual proportion of Toxoglossa, many of which are hand- 
somely sculptured and of large size, is a noteworthy feature. Tecti- 
branchs are also abundant and some of them large. Rhiphidoglossa are 
also relatively abundant and present some striking and elegant forms 
of 'Trochidz, while there are 13 limpet-like forms belonging to this 
group, including the genera Cocculina, Addisonia, Lepetella, Pro- 
pilidium. The Solenoconcha or Scaphopoda are relatively much 
more abundant, and some of the species are much larger in 500 to 
2000 fathoms than in shallow-water. This must be regarded as 
mainly a deep-sea group. 
Among Lamellibranchs the groups that are relatively most num- 
erously represented are the Anatinidze and Corbulide, (especially the 
genus Necra); the Nuculide, including the genera Nuewla, Leda, 
Yoldia, Malletia Glomus, ete.; and the Arcidie, including Arca and 
Limopsis. The Lucinide and Pectenidz are also well represented. 
