off the southern coast of New England. 301 
Issa ramosa Verrill aud Emerton, sp. nov. 
Body elevated, convex above, elongated, oblong, sides nearly 
parallel along the middle; foot well-developed, as broad as the 
bod orsal tentacles thick, clavate, obtuse, with numerous 
lamellz ; sheath scarcely raised. Back and sides with numer- 
ous small, simple papillae. Along the lateral margins of the 
back there is a carina, with a row of large, much branched 
papille, alternating with much smaller ones; of the large ones 
there are about six on each side, the most anterior are below 
transversely oblong plates; there are three rows of large, nearly 
equal teeth on each side, with the tips strongly incurved, ob- 
tuse; the innermost tooth has a small lobe on the middle of the 
inner edge: these are followed by about seventeen or eighteen 
smaller, oblong plates, with slightly emarginate anterior ends; 
a gradually decrease in size toward the margins of the 
a 
ula. 
Stations 940, 949; 130 and 100 fathoms. 
n form, this resembles Z. lacera, but is easily distinguished 
by the branched appendages along the sides. 
Of the Lamellibranchiata, some very interesting new forms 
occurred. The most important of these are species of Phola- 
domya, Mytilimeria and Diplodonta,—three genera not before 
found on this coast. The Pholadomya is more related to cer- 
tain fossil forms than to any of the few described living species. 
The genus Mytilimeria has hitherto had very few living repre- 
Sentatives, and none of them resemble our very singular 
Species, 
Among the northern forms, not previously found south of 
Cape Cod, are the following: Mya truncata; Spisula ovalis 
(975, 976, 981); Leda tenuisulcata (973); Nucula tenuis. 
Pholadomya arata Vervill and Smith, sp. nov. 
Shell triangular, short, wedge-shaped, posterior end angular, 
somewhat produced, obtuse; anterior end very short and ab- 
ered with deep, rather wide, concave furrows, separated by ele- 
vated, sharp-edged ribs; the furrows vary in width and decrease 
