EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA 73 



Pterinea moneris Clarke 



Plate 13, figures 6-9 



Pterinea moneris Clarke. N. Y. State Mus. Bui. 107. 1907. p. 202 



Somewhat oblique valves with hinge line less than the greatest length, 

 anterior beaks, and moderately developed posterior wing. The surface is 

 depressed and entirely devoid of radial markings on either body or wing, 

 thus only concentric lines or rough wrinkles are present. 



The umbonal teeth are strongly developed in the left valve as a set of 

 three oblique ridges, behind them being a strong oblique ridge. What may 

 prove to be the right valve of the species has a more convex surface, strong 

 anterior muscle scar and teeth to correspond with the sockets of the other 

 valve. 



This species is like but much more oblique than the P. follmann i 

 Freeh and P . 1 a e v i s Goldfuss of the Coblentzian. 



Locality. Webster lake, north side, ^ mile east of Telos canal and 

 Matagamon lake, on east side, i mile above dam, Me. 



Actinopteria textilis (Hall) 



See pt i, p. 156 



The specimens thus referred are apparently without departure from 

 the general expression of the shell as it occurs in the Helderbergian and 

 the Grande Greve limestones. The posterior wing is sometimes radially 

 marked and at others bears only concentric lamellae. 



Locality. Telos lake, i mile above Blind Cove point. 



" 



Cyrtodonta beyrichi Beushausen 



Plate 15, figures 4-6 



Cyrtodonta beyrichi Beushausen. Beitr. zur. Kenntn. d. Oberharzen Spiriferen- 



sandsteins. 1884. p. 67, pi. 3, fig. 2, 3 

 Cyrtodonta beyrichi Beushausen. N. Y. State Mus. Bui. 107. 1907. p. 214 



I am disposed to refer to this species without much reservation certain 

 subcircular shells of Paracyclaslike outline with quite convex surface, slightly 

 depressed behind and faintly sinuous in front. In these the hinge has the 

 structure of Cyrtodonta strongly developed the curved double anterior 

 teeth and the long lateral or posterior grooves and ridges. Beushausen's 

 figures were made from internal casts but they display the general outline 

 and size of those before us. 



The genus Cyrtodonta has not been observed in the Devonic rocks of 

 the Appalachian province and its occurrence in the eastern region is of 

 decided interest. While these Devonic species seem to agree in hinge 



