510 PALEONTOLOGY OF NEW YORK. 



anterior border of the shell. Posterior scar large, round, situated on the 

 post-cardinal slope. 



The two specimens observed measure respectively 67 and 72 mm. in 

 length, and 32 and 36 mm. in height. 



The species is represented by two specimens, both occurring in the Hamilton 

 group, and it is so distinct from any other form as to preclude comparisons. 

 Its general form and aspect is somewhat similar to some forms of Panop^a. 



Formation and locality. In the sandy shales of the Hamilton group, at Ful- 

 tonham, Schoharie county, N. Y., associated with Leiopteria Bigsbyi, Goniophora 

 Hamiltomnsis and Rhynchonella congregata. 



PROMACRUS, Meek. 1871. 

 Promacrus cuneatds. 



PLATE LXXVni, FIG. 28. 



Pholadella enneata. Hall. Prelim. Notice Lamellibranchiata, 2, p. 66. 1870. 



" decussate, " Pal. N. Y. vol. v, pt. 1. Plates and Explaiiation.s : PI. 78, fig. 28. 1883. 



Shell below the medium size, elongate, attenuate, sub-cuneate anterior to the 

 beak. 



The specimen is a fragment, preserving the anterior end and the beak. It 

 proves, upon comparison with Promacrus Missouriensis, to belong to the same 

 genus. It is distinguished by its smaller size, stronger and more regular con- 

 centric undulations, and distinct continuous radii of the surface, which become 

 nodose at their intersections with the concentric undulations. 



The specimen, anterior to the beak, has a length of 45 mm. and a height at 

 the beak of 24 mm. 



Formation and locality. In the Yellow sandstones, at Burlington, la. 



