NUCULA. 151 



Nacula proxima, Say, Journ. Acad. Nat. Sc. ii. 270 (1822). — Conrad, Amer. Mar. 

 Conch, pi. 6, fig. 2. — Goulu, Inv. Mass. 1st ed. 10.3, fig. 63. — Hanlev, Biv. Sli. 

 172, pi. 20, fig. 5; in Thes. Conch, iii. 151, pi. 229, figs. 131, 132. -De Kay, Nat. 

 Hist. New York, 179, pi. 12, fig. 21.5. — Stimpson, Shells of New England, 8; Inv. 

 Gr. Maiian. 20. — S. Smith, Moll, of Long Island, 1 5. — Mighels, Shells of Maine, 

 17, and Journ. Bost. Soc. iv. 323. 



Shell small, thick, and solid, very oblique, triangular, the outline 

 and angles a little rounded ; the anterior end nearly vertical, and 

 about two thirds the length of the posterior margin, forming some- 

 thing less than a right angle with it ; beaks somewhat elevated, in- 

 clined forwards ; anterior slope with a large, ovate area, 

 defined l)y an angular ridge ; posterior edge broad and 

 flattened ; surface crossed with somewhat coarse lines of 

 growth, and by very minute radiating lines ; epidermis 

 light olive color, with darker zones ; interior pearly, the 

 margin very finely crenulated ; cartilage pit very small ; scries of 

 teeth twelve before and eighteen behind the beaks, including the 

 very small ones near the pit, short and broad, the two series nearly 

 at right anales with each other. Lenoth, nine twentieths of an 

 inch ; height, near anterior margin seven twentieths of an inch ; 

 breadth, five twentieths of an inch. 



Found not uncommonly in the stomachs of fishes taken near 

 Nahant. Professor Adams found it abundantly at Dartmouth, in 

 mud taken up beyond low-water mark ; and Dr. Yale sent it to me 

 collected on the shores of Holmes's Hole. Marblehead Harbor, 

 seven fathoms (Haskell) ; Charles River below the bridges, Salem 

 Harbor, Grand Manan (Stitnpson) ; Casco Bay (Mi'j^hcls) ; Fishing 

 Banks (Willis ) ; Long Island Sound (Smith); whole coast, from 

 South Carolina (Stimpsori). 



By many, this shell has been supposed identical with the N. 

 nucleus of English authors, — the iV! marg-aritacea of Lamarck. 

 But actual comparison shows a wide difference. The N. nucleus is 

 less triangular, the posterior tip broadly rounded ; its proportional 

 diameter is not more than half as great, the epidermis is firm and 

 darker, the teeth are ten and twenty, and the whole shell is doul)le 

 the size of ours. It is much more closely allied to, if not identical 

 with, a shell sent me by Mr. Sowerby under the name of N. nit Ida. 

 The number and arrangement of teeth is the same ; and if there 

 be any difference, it is that the British shell is smoother, nar- 

 rower, the angle made hy the anterior and superior margins is 

 greater, and the shape less obliquely transverse. The stria; are 

 very obvious under the epidermis. In young specimens a scries 



