PL \ I 1. XVII i ontinaed 



I'l GRINOPEOTEN 8PONDTL1 8. 

 Page 65. 

 riir. L6. The interior of a left valve showing the spinous proce the rays projecting from the pallia] 



in. enlarged to two diameters. 

 Hamilton group. Canandaigua lake, X. Y. 



Pterinopecten conspectus. 



Page 66 

 IT. Fhe exterior of an imperfect righl valve as obtained from s gutta-percha cast of the natural mould. 

 Hamilton group. Skaneateles lake, X. Y. 

 Kg, 18. An exfoliated left valve. 



Hamilton group. Skaneateles lake, N. Y 

 Pig. l'ii. A specimen preserving the fine intermediate rays of the test. 



Hamilton group. Darien, Ghneset Co.. N. T. 

 Fig. 21. A left valve with the test removed. The ear is represented as inn oblinne in t'ne figure. 

 Hamilton group. Skaneateles lake, 2V*. Y. 



Pterinopecten intermedin. 



Page 6S. 

 See Plate 83. • 

 Pig. L9. A left valve enlarged to two diameters. 



Hamilton group. Cayuga lake, JY. Y. 



Pterinopecten filitextus. 



Page G7. 

 See Plate 82. 

 22. A right valve preserving the test and showing the form of this valve. 



Hamilton group. From a boulder, Pine Valla/. Chemung Co., X. Y. 



Actinopteria SUBDECUSSATA. 



Page 110. 



See Plate 19. 

 Pig. 23. \ small left valve. 



Pig. 25. A somewhat larger example. 



Pig. 26. An individual of limn size showing the form and surface markings. 



Pig. ^'7. A left valve, a large portii f which is broken away, show ing the interim- of the righl valve. 



Pig. 29. A large left valve. 



Fig. 30. \ right valve showing a greater extent of the winy than in the opposite valve. 



Kg. 31. A -i imenof medium size, showing the interior of the left valve occupied byaportion of the 



right, and representing the difference in the strength of the Burface markings on the two 



vah es. 



Hamilton group. All from Canandaigua lake, except fig. 29 which U from BeUona, 

 Yuhs Co., X. Y 



\i I INDI'TEIUA DECUSS VTA. 



Page in 



See Plates IS, 20 and 84. 

 Pig. 24. A small left valve. 



Hamilton group. Dresden, Totes Co., N. Y. 



Fig. 28 \ large lefl valve with the test removed, showing the usual form of the shell. 



Hamilton group. Canandaigua lake, X V 



