A. E. Verrill — Molhisca of the New England Coast. 223 



This species is very distinct from P. granulata and P. rotmidata 

 JeiF., both in form and in the character of the surface, which in both 

 the latter forms is covered with comparatively large, rounded 

 granules or small pustules, often closely crowded together, while in 

 this species the granules are almost microscopic in size and separated 

 by comparatively wide intervals, or they even appear remotely 

 scattered on some parts, so that the shell presents a nearly smooth 

 appearance to the naked eye, or when modei'ately magnified, which 

 is strongly in contrast with both the other described forms. The 

 form of the shell in this species is also much shorter and more tumid, 

 with higher umbos and more prominent beaks. The character of the 

 hinge, however, agrees pretty closely with that of P. granulata^ but 

 the tooth is larger and stronger. 



Neaera undata Yerriii, sp. nov. 



A large species remarkable for its short broad form, its abbreviated 

 siphon and the undulated character of the surface. Shell broad-ovate, 

 not much swollen, with the beaks not far from the middle. The pos- 

 terior dorsal margin descends rapidly in a nearly straight line ; the 

 posterior end is broadly, obtusely truncated and only slightly pro- 

 longed ; the ventral margin is very broadly curved ; the posterior 

 margin less broadly roimded. The surface, especially anteriorly, is 

 covered with undulations formed by narrow, raised, subtriangular 

 ridges separated by ratlier wide, shallow, concave intervals, much as 

 in most species of Asiarte. These fade out, more or less, posteriorly 

 and toward the ventral margin, where they are replaced by regular, 

 concentric, raised lines. Hinge-margin of the right valve moderately 

 thick. The cartilage-pit is not very large, descending, directed 

 obliquely backward. Posterior lateral tooth is not very prominent, 

 having the form of an elongated, thickened ridge, its most promi- 

 nent point only a short distance back of the cartilage. 



Length, 24"""; height, 18"^™; thickness, 13"^™. 



Station 2098, off Chesapeake Bay, in 2221 fathoms. A single 

 valve, considerably broken, (No. 35,256). 



Neaera gigantea Yeniii, sp. nov. 



Shell very large, thick and opaque, short, stout, with prominent 

 umbos, and short, wide beak, with the muscular scars and pallial lines 

 deeply sunken. The shell is swollen and broadly rounded in front, 

 with the ventral edge broadly rounded, narrowing gradually to the 



