DONAX FOSSOR. 



DESCRIPTION. 



2. D. fossor. Shell subtriangular; anterior margin 

 short and rounded; posterior hinge slope rectilinear; base 

 very slightly prominent beyond a regular curve at the 

 middle; valves longitudinally striated with numerous, 

 equal, parallel, regular, impressed lines, not visible to the 

 unassisted eye, and obsolete on the posterior margin; 

 hasal edge within crenate; colour pale-livid, with two lon- 

 gitudinal whitish rays before the middle, both within and 

 without. 



Var. a, Whitish. Var. b. Yellowish. 



SYNONYM. 



DoNAx FOSSOR, Noh. Jour. Acad. Nat. Sciences^ vol. ii. p. 

 306. 



OBSERVATIONS. 



Inhabits the coast of New Jersey and Maryland. 



Cabinet of the Academy and Philadelphia Museum. 



Very numerous under the surface of the sand, which 

 is exposed at the recess of the tide. A wave by remov- 

 ing the surface of the sand, exposes a great many indi- 

 viduals to view; at its refluence, these immediately pene- 

 trate the sand, and before the recurrence of the surge 

 they are concealed. 



They are preyed upon by several shore birds and fish: 

 the drum (Scigena chromis) and sheep's-head, (Sparus 

 ovicephalus) are sometimes caught in the surf in con- 

 siderable numbers, whilst in pursuit of them. 



PI. 61— Fiff. 2. 



