110 NEW YORK STATE MUSEUM 



PLATE 4 



Actinopteria communis Hall 



Page 34 

 Pio. 



1, 2 Right and left valves of the same shell, showing the char- 

 acter of the surface 



Pterinopecten signatus sp. nov. 



Page 33 



3 A left valve showing the form and external ornament 

 Pterinopecten proteus sp. nov. 



Page 32 



4-7 Right and left valves of this species, which show the wide 

 variation in external characters 



8 An enlargement of the surface characters of one of these 



shells. x2 



Pterinopecten pumilus sp. nov. 



Page 33 



9 The right valve of this species. x3 



Actinopteria insignis sp. nov. 



Page 35 



10, 11 Two left valves showing the form and external characters 



of the species 

 12, 13 Enlargement of the surface characters from different parts 



of the same shell. x5 



Pterinopecten subequilateralis Hall (emend.). 



Page 31 



14 An external cast of the surface of a right valve, showing 

 the absence of radial ornament 



