DENTALIUM. 265 



of the valves is smooth, with three radiating- lines passing from the 

 beaks to the middle of each base, encloshig two ronnded, thread-like 

 ribs. It is also covered with a thin meml)rane, coated 



Fig. 527. 



with a dirty, scurfy epidermis which is easily rubbed 

 otf. Margin broad and thick, resembling macerated 

 calf-skin, coated like the rest of the surface, and hav- 

 ing two ranges of small tufts of yellowish hair, two 

 on each of the intermediate, and six or eight around 

 the terminal valves. Length, four fifths of an inch ; 

 breadth, six tenths of an' inch. ^- ^— «"• 



Found in stomachs of fishes taken in Massachusetts Bay. Bed- 

 ford Basin, N. S,, common ( Willis) ; Cape Cod, northward (^Stimp- 

 son) ; fossil, Montreal (^Daivso^i). 



This is a very curious shell, and, with three or four other de- 

 scribed species, might constitute a sub-genus. It is so rough and 

 unseemly that it is very likely to be rejected as some decayed speci- 

 men ; or the discoverer would begin to clear off, as some extraneous 

 substance, the coating which belongs to it, and gives it a character. 



The shape of the valves, the sculptured areas, and the emarginate 

 anterior valve, will not allow it to be confounded with any other 

 species. Could it be presumed that so remarkable characters as the 

 central areas and the anterior valve were overlooked, we might sup- 

 pose this to be the C. vesiiius, Broderip and Sowerby (Zool. Journ. 

 iii. 368). The areas, however, are easily defaced, and might not 

 have attracted notice in their specimens. In other respects their 

 description would apply well to our shell. The figure recently given 

 of it in the Appendix to Beechey's Voyage, tab. 41, fig. 14, repre- 

 sents a shell proportionally much narrower than ours. 



Family DENTALIID^. 



Animal with the branchiae in the form of numerous long fila- 

 ments, arising from two radical lol:)es placed above the neck, and 

 enveloped, with the head, by the mantle. Shell tubular, not spiral. 



Oentis DENTAHUWI, Li^. 1740. 



Shell tulmlar, elongated-conical, slightly curved, opening at each 

 end by a rounded orifice, that of the apex entire, without fissure or 

 emargination. 



