1887.] NATURAL SCIENCES OP PHILADELPHIA. 405 



From Ayres' pits near Sliiloh. Fairly abundant. From the col- 

 lection of Miss Mary S. Holmes, of Philadelphia. 



Triforis terebrata. nov. sp. 



Spire gradually tapering, nearly parallel-sided; whorls? flat, orna- 

 mented (on the body-whorl) with two prominently beaded lines, 

 and two alternating lines of smaller beads ; on the whorls above the 

 body-whorl the lowest line is indistinct, or entirely covered over; 

 transverse lines connect the beads of the different series ; columella 

 smooth, arcuate. 



Length, ? 



A fragment only, showing three whorls, from Ayres' pits, near 

 Shiloh ; in the possession of Miss Ella Lyndall, of Philadelphia. 



The species appears to be most closely related to Cerithium ( Tri- 

 foris)'moniliferwn, of H. C. Lea. 



Pecten Humphreysii, var. Woolmani. 



Under this name I propose to designate a Pecten, which appears 

 to be only a variety or sub-species of the Maryland P. Humphreysii, 

 difiering from the normal type of that species in the greater eleva- 

 tion of the ears, and the more distinct quadrangulation of the ribs 

 of the convex valve. The ribs are also more prominently lined. 

 All the New Jersey specimens that I have seen of what appears to 

 be Pecten Humphreysii agree in these characters. 



Illustrations of these species will be given in a future paper. 



Noie. Since the preparation of the above Mr. Woolman has obtained from the 

 Atlantic City boring Nassa obsoleta, the impression of a fish-scale, and several 

 Foraminifera [Cristellaria, Robulina, etc.) 



