PLATE XIX. 



Leioi'tkkia Dekayi. 

 e 164. 

 See Plates 20 and B8. 

 i A small left valve. The specimen shows no indications f rays such as are represented in the 

 figure. Hamilton group. Cooperstoum, N. Y. 



ACTIXOPTEIM \ P>()Vi>I. 

 Page 113. 

 See Plate 84. 

 I"i_- 2, 3. Two lefl valves preserving the surface ornamentation, 

 Hamilton group. Sehoharu Co., N. Y. 

 A lefl valve. 

 A small lefl vah e. 



Hamilton group. Jefferson, Sehoharii ''".. If, Y. 

 A righl valve with an unusually extended wing. 



Hamilton group. Fultonham, Sehoharu Co., N. Y. 

 The exterior of a right valve, as obtained from a gutta-percha impression of the natural mould, 

 showing the spinous processes of the lamella. 



Hamilton group. Bultonham, Sehoharu Co., X. Y. 

 The preceding figures represent the forms described as Aviculu qvadruUz, Conrad. 

 Pig. 8. A small left valve. The ear should be represented as somewhat oblique. 



Hamilton group. Jefferson, Schoharie Co., A. 1*. 

 Pigs 9-11. Three lefl valves showing gradation in size and slight differences in form and surface char- 

 acters. 

 Pig. 12. A small right valve enlarged to two diameters. Another figure of this specimen is given of the 

 natural size in tig. 17. pi. 84. 



Hamilton group. Hamilton, Madison Co., N. Y. 

 Pigs 13-15. Three left valves differing slightly in form and surface ornaments. 



Hamilton group. Schoharie Co., X. Y. 

 Figs. 16-20. A series ofleft valves representing the type .1. Boydi of Conrad. 

 ji 23. Right valves associated with and corresponding to the preceding. 



Pig. 24. Two individuals, each retaining both valves in contact. 



Hamilton group. Figs. Hi and 17 are fi i SclioharU County; the others are from 



Ona t.l, i, /a and Madison comities. X. Y. 



Figs. 26, ■!",. Two large left valves. 



Hamilton gTOup. Cazenovia, Madison ' '".. If. Y. 

 28 The righl valve of the specimen, fig. 2d. showing the comparative size of the two valves. 

 Fig. 29. Cardinal view of the preceding. Another view of the left valve is given on plate 84, tig. Id. 

 Fig. :;<i A righl valve showing unusually fine concentric striae. 



Hamilton group. Caeenovia, 2V. F. 



ACTINOPTERIA SUBDECUSSATA. 



Page 110. 



See Plate 17. 

 Pig 25. A left valve showing the characters as preserved in a coarse shale 

 Hamilton group. Cazenovia, 2V. Y. 



ACTINOPTEEIA PEROBLIQUA. 



Page 116. 



See Plate 84. 



Fig. 31. The right valve of the specimen described. The left valve of this sj tmen is figured on plate 84, 



tig. 14. Hamilton group. Cazenovia/ N. Y. 



