22 



Fossils of the Utica Slate, 



Genus — SAGENELLA Hall 1852. 

 Sagenella ambigua n. sp. 



Plate I, figures 3, 3a. 



Cells arranged in regular parallel series over most of the surface, 

 quadrangular and oblong shaped in the parallel series, and where 

 this series is broken they are more or less oval, several series are 

 intercalated giving the cell walls the appearance of the bifurcating 

 branches of a Dictyonema. The striations visible on the cell walls 

 and transverse septa are owing to the impression of the striated 

 surface of the shell of the Endoceras to which the bryozoan was 

 attached. 



Formation and locality, Utica slate, town of Trenton, Oneida 

 Co., N. Y. 



Genus — MODIOLOPSIS Hall 1847. 



MODIOLOPSIS CANCELLATA U. Sp. 



Plate I, figure 8, 8a. 



General form subelliptical, convex ; cardinal line nearly straight 

 from the beak to the posterior margin ; anterior end rounded from 

 the cardinal line to the basal margin. 



Basal line arcuate ; posterior end obliquely truncate, umbonal 

 ridge broadly rounded with a uniform convexity, to the basal 

 margin. 



Surface marked by strong concentric and radiating striae, 

 which are strongly developed on the posterior half of the shell ; the 

 crossing of the striae gives a cancellated appearance which is not 

 seen on the closely related Modiolopsis anodontoides. The broad 

 umbonal ridge also distinguishes it from that species. 



Formation and locality, Utica slate, town of Trenton, Oneida 



Co., N. y. 



Genus — ORTHOCERAS Beeynius 1732. 



Orthoceras Oneidaense n. sp. 



Plate I, figure 7, 7a. 



Besides the very common Endoceras proteiforme, which occurs 

 in great numbers, there are two forms of Orthoceras in the beds from 



