152 PALAEONTOLOGY OF NEW-YOllK. 



191. 1. TELLINOMYA NASUTA (n. 5;;.)- 



Pl. XXXIV. Figs. 3 a, b, c. 



Transversely elongated, inequilateral ; anterior extremity rounded ; posterior extremity 

 greatly extended into a kind of beak, which is narrowed and compressed, contracted on 

 the base by a shallow sinus ; umbones prominent, rounded ; shell thin ; surface marked 

 by fine concentric lines. Tlie muscular impressions are strongly marked upon the cast, and 

 the umbones are more obtusely angular ; there is no evidence of teeth or crenulations. 



This shell is readily distinguished by the prolonged posterior extremity, which is obliquely 

 truncated and constricted by a sinus on the base. This character is more conspicuous on 

 the cast than in the perfect shell ; the anterior portion of the shell is more gibbous, and 

 regularly rounded at the extremity. 



This is a rare species, the form of which I was at first inclined to regard as accidental ; 

 but having seen three specimens in which it is constant, there can remain no question of 

 its title to a place among the species of this period. 



Fig. 3 a. Eight valve of a specimen on which the shell is preserved. The posterior side of the shell is 



less extended than in the other specimens. 

 Fig. 3 h. Similar view of a cast, showing the muscular impressions a a. 

 Fig. 3 c. Dorsal view of the same. 



Position and locality. In the dark colored upper portions of the Trenton limestone at 

 Middleville, Trenton Falls, &c, 



192. 2. TELLINOMYA SANGUINOLAROIDEA (n. ^^.). 



Pl. XXXIV. Figs. 4 a, b. 



Inequilateral, transversely extended, compressed, subelliptical, narrowed posteriorly ; 

 anterior extremity broadly semi-elliptical ; posterior half sul>cuneate, compressed and acute ; 

 umbones (in the cast) moderately jjrominent, thin, approximate ; cardinal line extended, 

 without visible teeth or crenulations; basal margin regularly curved ; shell thin, closely 

 marked by fine concentric laminas. 



The only specimen which I have been able to obtain is a cast, and I have seen another 

 in the same condition. It is readily distinguished from the last, by being more compressed, 

 the umbones less prominent, the front more uniformly and regularly rounded, while the 

 posterior extremity is cuneate and the basal margin regularly curved, presenting no evidence 

 of a sinus or depression as in the last. 



Fig. 4 a. Right valve, showing the posterior muscular impression a. 

 Fig. 4 b. Cardinal view of the same specimen. 



Position and lucality. In the lower part of the Trenton limestone at Canajoharie and 

 Middleville. 



