Desci'iptlons oj J^ew Genera and Species of Fossils. 25 



Surfixce of the left vjilve marked by fine concentric lines, and at 

 irregular intervals by rather strong furrows. 



Length of large example, one half an inch; width, one quarter of an 

 inch or a little more; couvexit}- of left valve about one sixteenth of 

 an inch. 



The peculiar outline of this species will at once distinguish it from 

 any other form known to the writer. 



Formation and locality: in the soft shales of the lower fift}' feet of 

 the Hudson River Group, at Covington and Constance, \s-\. 



Collectors: H. E. Dickhaut, E. O. Ulrich. 



Cleidophords ELLiPTicus, n. sp. (Plate VII., fig. 22). 



Shell small elliptical, moderately and evenly convex; beaks a little 

 more than two fifths of the length of the shell from the anterior end; 

 umbones very little eleA'ated ; anterior and posterior margins regularly 

 and evenly rounded; cardinal and basal lines both genth' curved; 

 clavicle slightly curved forward, and extending obliquely from in front 

 of the beak to a point more than half the distance to the anterior basal 

 margin. 



Surface marked by ver3' fine sub-equal concentric stria?. 



Height of medium sized specimen, 0.18 inch: length, 0.3 inch; con- 

 vexity, 0.1 inch. 



This species is allied to C. si(,bovatKS, Hall, described from the Ari- 

 saig Formation of Nova Scotia, but that shell is larger, has different 

 stria?, the beaks situated near the anterior extremitv, and a shallow 

 sinus. 



Formation and locality: this species was found by Mr. Henry E. 

 Dickhaut in the lower part of the Hudson River Group, at Covington_ 

 at an elevation of about one hundred and fiftj- feet above low water 

 mark in the Ohio River. 



Cleidophorus major, n. sp. (Plate VII., fig. 23). 



iEty. —.Ifajor, large). 



Shell sub-ovate, ventricose, height and length respectivel}- as 5^^ 

 to 10; umbones rounded and prominent; beaks elevated, sub acute 

 about one-fourth the entire length of the shell from the anterior mar- 

 gin; posterior cardinal line nearly straight, with a strongly defined 

 sharp, umbonal ridge extending from the beaks and gradually' becom. 

 ing obsolete toward the posterior margin; the space between the ridge 

 and cardinal line slight!}' depressed; anterior margin rounded; basa 



