242 NEW YORK STATE MUSEUM 



The external molds of the striae are crenulate. It was found in the 

 Lower and Upper New Scotland and probably in the Becraft. 



S. leavenworthana Hall 

 A single specimen was found and this in the lower part of the Port 

 Ewen. This is strongly geniculate toward the front of the shell, 

 while the posterior portion, after a slight depression at the genicula- 

 tion rises but little over low concentric wrinkles to the umbo. 



S. punctulifera (Conrad) 



Usually occurs only as external and internal molds. The brachial 



valve of this species is deeply concave at the umbo but becomes 



strongly geniculate toward the front. The puncta are usually poorly 



preserved. It occurs, but in moderate abundance, in the Coeymans, 



Upper New Scotland and Port Ewen ; one specimen represents it in 



the Becraft. 



Orthothetes woolworthanus Hall 



Hall describes the surface of this as being covered with fine, 

 rounded striae.^ It is a rare species and is represented in our col- 

 lection by several specimens from the New Scotland and Becraft. 

 One well preserved brachial valve, measuring 28mm by 34mm, is 

 flattened in the region of the umbo but becomes quite convex toward 

 the front. The surface is covered with numerous, very fine, rounded, 

 radiating striae. 



Orthis sp. 



In the Eower Oriskany several specimens of a large Orthis were 

 found but they were all too poorly preserved for identification ; they 

 much resembled Rhipidomella musculosa (Hall) . 



Chonetes hemisphericus Hall 

 Quite abundant in the Onondaga. The specimens agree very 

 closely in average size, convexity and striae v/ith those described by 

 Hall.2 



C. hiidsonicus Clarke 



Several specimens from the Eower New Scotland are referred to 

 this species. One of medium size measures 9mm by 15mm by 



*Weller speaks of the striae in the New Jersey specimens as angular. 

 Geol. Sur, N. J. Paleontology. 3:278. 

 *Pal. N. Y. 4:118, pl.20, fig.6a-d. 



