212 NEW YORK STATE MUSEUM 



except on the posterior wing near the hinge, only the concentric 

 lines standing out sharply and equidistant. The inner surface of 

 both valves is quite smooth. This is a striking species well defined 

 by its outline and surface characters. Its thin shell has left insuffi- 

 cient evidence of its dentition but I have referred it to Pteronitella 

 largely because of its general aspect. 

 Lower Devonic. Dalhousie, N. B. 



Pteronitella passer nov. 



This differs from the preceding in presenting a less extended and 

 rather blunt posterior extremity, a more conspicuous anterior ear 

 and a relatively greater breadth. The outline is still elongate 

 with a gentle surface slope on all sides except the front where it 



Pteronitella passer 



is quite abrupt. The surface is fully reticulated by radial and 

 concentric lines, the former being as before stronger along the 

 posterior wing. 



In my judgment this will be readily distinguished by its outline 

 as exhibited in two left valves here figured, though it is undeni- 

 ably similar to P. h i r u n d o in many of its characters. 



Lower Devonic. Dalhousie, N. B. 



Pteronitella peninsulae nov. 



Very sharp internal casts of right valves show the characteristic 

 structure of this genus as defined by Billings, clearly demonstrat- 

 ing the departure from the type of Pteronites in the presence of a 

 series of Cyrtodontalike teeth beneath the beak together with the 



