228 Twenty-fourth Report on the State Museum. 



oblique, pointed below ; hinge line short; beak very small. Hinge 

 plate occupied by six angular, crenulated, radiating teeth, which, 

 diverging from beneath the beak, are strongly arched upwards 

 between their origin and extremities; crenulations minute but very 

 distinct; muscular impressions and pallial line not observed. 



DiiFers from L. jpoststriati and L. plana in the much shorter form 

 and in number of teeth. 



Formation and locality. In the Hudson-river group at Cincinnati, 

 Ohio. From Mi-. C. B. Dyer. 



Tellinomta pectunculoides n. sp. 

 Plate 7, fig. 2G. 



Shell small, subcircular in outline, with the posterior end slightly 

 prolonged below the middle, giving a little obliquity to the shell ; 

 posterior cardinal border obliquely sloping to the point of greatest 

 extension ; anterior and basal borders regularly rounded ; beaks 

 small ; general surface of the valves depressed convex. Hinge plate 

 strongly arcuate, more abruptly curving in the middle, occupied by 

 ton or twelve teeth on each side of the center, those in the middle 

 being nearly straight, becoming more and more bent and angular 

 toward the extremities; muscular impressions large and distinct; 

 pallial line strongly marked, situated considerably within the border 

 of the valve. 



Surface characters of the valves not observed. 



This species is more nearly circular than any species yet described 

 from rocks of this age, and may be easily distinguished by this feature 

 as well as the gentle convexity of the valves. 



Formation and locality. In shales of the age of tlie Hudson - 

 river group, at Cincinnati, Ohio. In the cabinet of Mr. C. B. Dyer. 



Genus— CLIDOPHOEIIS Rail. 

 Palaeontology of N. Y., vol 1, p. 300. 



When originally described, the species of this genus were supposed 

 to be destitute of hinge teeth, or at least of crenulations like the 

 Nuculse. Several years since, however, I had determined that some 

 western forms referred by me to the genus were crenulate on the 

 hinge line, and during the past year the same character has been 

 observed in the typical forms of the genus from the Hudson-river 

 shales of New York. Should the arrangement of the crenulations 

 prove the same as in Nuculites, it will probably be found to possess 

 no other distinction sufficient to separate it from that genus. 



1 



