NUCULA. 149 



distant from each other. Apices separated by a long narrow space, 

 and sitnated at the termination of the posterior (anterior) third of 

 the length of the hinge-margin ; extremities of the hinge-margin 

 angulated ; anterior (posterior) edge, the 

 snperior half rectilinear ; posterior (ante- ^'^' ^^^ "' 



rior) edge rounded ; inferior edge nearly- 

 rectilinear, or very obtusely rounded ; on 

 the hinge space, one or two angulated lines 

 are drawn from the ajjcx diverging to the 

 hinge edge." {Sai/.') Length, one and a 

 half inches ; height, one inch ; breadth, 

 one and a half inches. 



Found about the sands of Nantucket and Martha's Vineyard, and 

 it is said to be not uncommon in Buzzard's Bay. Osterville (^Has- 

 kell) ; Gull Island (>S. Smith} ; from Artesian well, Provincetown, 

 one hundred and twentv to two hundred feet below surface. 



I have quoted the description by Mr, Say, above, merely inter- 

 changing the terms anterior and posterior, to accord with the parts 

 of the shell to which those terms are applied in other parts of the 

 Report. The position of the beaks distinguishes it from the pre- 

 ceding species, as well as the form of the shell. 



Ocnus IVUCULA, Lamarck. 1799. 



Shell transverse, without an area for the ligament between the 

 beaks ; a straight series of teeth each side, forming an angle at a 

 spoon-shaped pit which separates them. 



Nucula tenuis. 



Fig. 64. 



Shell trapezoidal, thin, smooth, without radiating lines; epidermis grass-green; 

 beaks prominent, placed posteriorly ; margin simple, teeth very few. 



Area tenuis, Montagu, Test. Bi-it. Suppl. 56, pi. 29, fig. 1. — Dillwtn, Catal. i. 246. — 

 TuRTON, Conch. Diet. 11. — Wood, Ind. Test. pi. 10, fig. 45. 



Nucula tenuis, Turton, Brit. Biv. 177. — Fleming, Brit. Anim. 402. — Brown, 111. 

 Conch. G. Br. 85, pi. 33, fig. 13. — Hanley, Recent Shells, i. 171, pi. 10 (Area), fig. 

 45. — McGiLLiv. Moll. Aberd. 244; Br. Mar. Conch. 105. — Forbes and Hanl. 

 Br. Moll. ii. 223, pi. 47, fig. 6, and pi. P. fig. 5 (animal). — Loven, Ind. Moll. Scand. 

 34 — MiGHELS, Shells of Maine; Bost. Journ. iv. 323. — Stimpson, Shells of New- 

 England, 8. — Packard, Labrad. Mar. Au. 13. — Sowerby, Conch. 111. No. 33, 

 figs. 140, 141. 



