SOME NEW DEVOXIC FOSSILS 



20 1 



toward the body of the shell is but slight, but the area is set off 

 by a low, broad depression on the surface and a distinct change 

 of curvature in the surface lines. The body of this shell is broad 

 and transverse, the curvature being regularly suboval, while the 

 anterior course of the margin is much more direct, curving out- 

 wardly below and slightly incurved above. The anterior wing is 

 very small, separated from the umbones by a deep sulcus. The 

 ligament area is very broad and is longitudinally lined. The orna- 

 ment lines of the surface consist of distinct concentric lamellae, 

 becoming more closely arranged near the margins. Their inter- 

 spaces are crossed and the lamellae themselves notched or cren- 

 ulated by subequally distant elevated radial lines. The reticulated 

 and fimbriated effect is specially shown on the posterior wing. 

 Our specimens show the following dimensions : Length on hinge, 

 100 mm, hight and length of body. 90 mm. 

 Lower Devonic. St. Alban beds, Cape Rosier Cove, P. Q. 



Pterinea mainensis nov. 



Shell often of large size, oblique, hinge considerably shorter 

 than the full length of the valve. Anterior wing well developed, 

 but slightly sloping at the hinge and set off from the shell body 



Pterinea mainensis 



by a low broad sulcus. Posterior wing relatively short not reach- 

 ing the posterolateral limit of the valve and sometimes not more 

 than one half or two thirds this distance. Body of the valves de- 

 pressed not sharply set off from the wings ; anterior outline at first 

 direct, then inclining more or less rapidly backward and often 



