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NEW YORK STATE MUSEUM 



added by division of the large ones. All are crossed by a con- 

 centric ornament of fine compressed lines with occasional deep 

 concentric growth furrows. This type of ornamentation is an 

 extreme condition of that sometimes expressed by Pterinopec- 

 ten proteus. The original specimen has a hight of 50 mm 

 and a probable length of 70 mm. 



Lower Devonic. Grande Greve, P. Q. 



Actinopteria (Pterinea) fronsacia now 



This is a species having somewhat the aspect of the common 

 and well known A. b o y d i of the Hamilton fauna of New 

 York, but more erect and with a larger auricle. Its surface 

 is marked by quite regularly alternating radii and these are crossed 

 by imbricating concentric lines which are closely crowded together 



Actinonteria (Pterinea) fronsacia 



and crenulated fore and aft. In A. b o y d i the radial riblets are 

 of more uniform size and as usually preserved in the shales show 

 only inconspicuous evidence of the lamellose concentric lines here 

 present. More closely allied in ornament and in form is the A. 

 e s c h w e g i i Clarke 1 , from the Lower Devonic Maecuru sand- 

 stone of the Amazonas. 



Middle Devonic. Gaspe Basin, P. Q. 



1 Archivos do Mus. Nac. Rio de Janeiro. 1899- 10:45. pi- 5. fig- 9- 



