78 INVERTEBRATA OF MASSACHUSETTS. 



brownish-yellow color. In proportions it agrees with the type spe- 

 cimens. 



Var. A. iwoccra^ inhabits Provincetown harbour, and is fully de- 

 scribed and figured by Colonel Totten in " Silliman's Journal," as a 

 probable variety of A. casianea, but as possibly a distinct species. 

 Its variation consists in its very light-colored epidermis, and the great 

 elevation of its beaks. The color of all the shells in that harbour is 

 remarkably light, as is noted of Mactra solidissima and Mya arendria, 

 so that in regard to its color it is merely a local distinction. The 

 elevation of some of the specimens is remarkable ; but these are 

 found living intermingled with those of the normal form, and are 

 found of every intervening degree of elevation. The shell in all its 

 varieties, but in this one in particular, strongly reminds one of the 

 termination of the recurved, round-pointed table or fruit knife. The 

 foot of the animal has the same vermilion-color ; and, on the whole, 

 this must be regarded as merely a variety. The proportions of the 

 most elevated specimen figured by Colonel Totten are ; length ^ inch, 

 height 1 inch, width ^ inch. 



AstArte sulca'ta. 



Shell ovate-triangular^ the surface icith deep, concentric furrows 

 and ribs, vanishing at the extremities ; beaks prominent ; lunule and 

 corselet long, narrow, and deeply excavated. 



Figures 45, 46. 

 State Coll., No. 206. Soc. Cab., No. 1805. 



Venus sulcata, Montagu; Test. Brit., 131. Pennant; Brit. Zool., iv. 203. 



Maton and Rackett, Lin. Trans , v'ni. S\, pi. 2, f. 1. Dillwyn ; CataL., i. 



167. Turton ; Conch. Diet., 235. 

 Astarte sulcata, Fleming ; Brit. Jlnim., 439. 

 Venus Danmonia, Montagu ; Test. Sn't., 45, t. 29, f. 4. Pennant; Brit, Zool., 



iv. 212. Wood; /wrfcj;, pl.7, f. 21. Dillwyn ; Caiai., 167. 

 Venus Danmoniensis, Blainv. ; Malacol., 557, pi. 75, f. 7. 

 Crassina sulcata, Turton ; Brit. Biv., 131, pi. 11, f. 1, 2. 

 Crassina Danmoniensis, Lam.; jln. sans Vert., vi. 257. Deshayes ; Encyc. 



M6th., Vers, i. 77. 

 Astarte Danmoniensis, Sow ere y ; Genera, f. 1 to 3. Totten ; SiUimans Journ. 



xxviii. 349, f. .3. 

 Venus Scotica, Montagu ; Test. Brit., 4i (the young). Maton and Rackett; 



Lin. Trans., viii. 81, pi. 2, f. ,3. Turton; Brit. Biv., 130, pi. 11, f. 3,4. 



Conch. Diet., 236. Wood ; Index, pi. 7, f. 20. 



Shell sub-orbicular, in some specimens approaching to ovate, 

 in others to triangular, thick and strong, somewhat compressed ; 



