360 Description of some New Shells. 



Art. XL — Description of some new Shells, belonging to the coast of 



New England; by Jos, G. Totten. 



Solemya borealis. 



See the plate. Fig. 1. h. i. 



Shell thin and fragile, oblong : hinge edentulous, placed near the 

 anterior end, with a slightly prominent cartilage, and an interior ele- 

 vated callus, which is hollowed and forked beneath, the lower portion 

 being directed towards the anterior-basal margin : valves distinctly 

 wrinkled concentrically along the anterior-dorsal margin, elsewhere 

 radiated with from fifteen to twenty sets of lines, which consist of 

 two lines, and are distinct on the anterior and posterior portions, and 

 of more numerous and rather indistinct lines on the middle of the 

 valve : epidermis dark brown, lighter between the sets of lines, very 

 glossy, extending much beyond the basal and lateral edges of the 

 valves, and, at the hinge-margin connecting them together nearly the 

 whole length of the shell : within grayish blue : umbo destitute of 

 the slightest elevation : anterior and posterior margins rounded : 

 superior and inferior margins nearly parallel, the former rectilinear 

 except at the ligament where it is slightly emarginate, the latter a lit- 

 tle arcuated* 



Length, 2*65 inches. 

 Breadth, 0-85 of an inch. 

 Diameter, 0-55 of an inch. 

 Inhabits the coast of Rhode Island. 



I have found this shell only in the vicinity of Newport, where it 

 is very rare — and I do not know that it has been found elsewhere. 



On comparing the above with Say's description of S. velum 

 (Journal of the Academy of Natural Sciences of Philadephia — vol. 

 2. p. 317) it will be perceived that there is a close accordance 



•his language, wherever it would apply, having been purposely 

 adopted : still there is thought to be a specific difference, because, 



1st. as to size. — A great many shells answering his description 

 have been found near the locality of the above shell, but none of 

 greater length than one inch. 



2d. as to color. — There are now before me specimens of the 

 present shell from the length given above down to the length of one inch, 

 and the color is, alike in all, dark brown without, and grayish blue with- 

 in, and 



