Pprkins.] 158 [November 3, 



none, but a long narrow fold of the branchial membrane on each side 

 of the mouth takes their place. 



NUCULID^. 



Nueula proxima Say, Am. Conch., p. 94, 1822; Gould, Invert. 

 Mass., p. 103, fig. 63; De Kay, Moll. N. Y., p. 79, pi. xii, fig. 215. 



Not common on the beach, but obtained plentifully by dredging. 

 Animal white; mantle freely open, margin double, ruffled, striated; 

 gills small, elongate-triangular, outer a little the longer, broad an- 

 teriorly, tapering to a point behind; foot flattened, cylindrical, end- 

 ing in an oval disk, which is thin, serrate on the edges, with numerous 

 short, thick papillae, striated on both sides, and when withdrawn, 

 folded together through the middle ; palpi two pairs, outer with a thin 

 parchment-like end, below which is a narrow striated lamina folded 

 upon itself longitudinally; inner pair linear, long, united about the 

 mouth; siphons wanting. 



Nueula radiata De Kay, Moll. N. Y., p. 179, pi. xii, fig. 216. 



Shells answering to this description are found here, but I believe 

 that the species is founded merely upon the young of N. proxima, 

 and ought therefore to be united with it, but as I have not absolute 

 proof that this is so, I leave it separate. 



LEDID^. 

 Yoldia Mull.; 1832. 



Yoldia limatula Woodward, Man. Conch., p. 429, fig. 220. 

 Nueula limatula Say, Am. Conch., p. 63, pi. xii, 1831 ; Gould, In- 

 vert. Mass., p. 98, fig. 62; De Kay, Moll. N. Y., p. 183, pi. xiii, fig. 

 218. Leda limatula Stimpson, Shells of N. E., p. 10. 



Not common, scarcely ever found on the beach, but obtained 

 abundantly by dredging a few miles off the lighthouse in four to six 

 fathoms. Mantle open, edge somewhat thickened, plain anteriorly 

 for about a third of its length, the remaining two thirds are fringed 

 with about fifty moderately long, simple papillse, some of which are 

 forked at the end ; gills small, narrow, coarsely striated ; foot long, 

 subcylindrical, increasing in size towards the end, which is obliquely 

 truncated, deeply cleft and furnished with short? rounded papillae; 



