LOWER HELDERBERG ROCKS. 
267 
Cypricarclinia dorsata (n. s.). 
Plate XLIX A. Fig. 2. 
Shell transversely elongated, scarcely gibbous : umbones depsessed; 
anterior extremity rounded; posterior extremity obliquely subtruncate; 
the cardinal margin compressed, with an obtuse oblique ridge separating 
t 
it from the body of the shell. 
Surface marked by concentric ridges, which are more conspicuous on 
the anterior part of the shell, becoming obsolete on the middle and 
posterior portions (perhaps from maceration and wearing before the 
shell was imbedded). 
The only specimen observed is in a skaiy limestone, and is not well preserved. 
It diifers, however, conspicuously from any other species seen in this group. 
Fig. 2. The right valve of this species. 
Geological position and locality. In the shaly limestone near the upper part of 
the Lower Helderberg group : Near Hudson, Columbia county. 
Cypricardinia suMamellosa (n. s ). 
Plate L. Fig. 1. 
Shell transversely elongated; anterior extremity contracted; umbones 
very depressed; posterior slope convex, without a defined ridge; ex¬ 
tremity somewhat acutely rounded. 
Surface marked by rounded concentric striae or ridges, which are more 
prominent on the posterior half of the shell. 
A single specimen only has been observed. 
Fig. 1. The right valve, natural size. 
Geological position and locality. In the compact calcareous layers of the middle 
portion of the Lower Helderberg group : Helderberg mountains, Albany county. 
