PLATE XVII. 



ACTINOPTKRIA MUEICATA. 



I'aji' 108. 



Fig. I. A small left valve showing the extent of the wing, X 2. The surface of the wing should show 



several fine radii. 

 Fig-. 2. A larger left valve, X 2. The extremity of the wing is not sufficiently extended in the figure, and 



the surface has fine radii which are qo1 represented. 

 Fig. 3. A left valve preser: Lng the mucronate extensions of the radii along- the ventral margin, X 2. 

 Marcellus shale. Littleville, Livingston Co., iV. Y. 



Actinopteria Doris. 



Page 109. 

 Fig. t. A left \ alve of this species, enlarged to two diameters. 

 Mai llus shale. East Bloomfidd, N. Y. 



Leiopteiua L.EVIS. 



Page 158. 



See Plate 20. 



Figs. 5, (!. Two right valves, X 2. Fig-, 6 is incorrectlj restored mi the ventral margin ami the win. 

 Figs. 7-11. Left valves showing the prevailing characters of the species, X 2. 

 Marcellus shale. Livingston and Brie counties, X. Y. 



Leptodesma Marcellexse. 



Page 175 

 Fig- 12. The left valve described, X 2. 



Marcellus shale. East Bloomfidd, N. Y 



Pterin* >pectex Hermes. 



Page 64 

 Fig. 13- A small left valve. The extremity of the oar is represented too acute and the pallial margin is 

 reflexed in the specimen. 



Hamilton group. I'miii mhiii/ua lake, N. Y. 

 Fig. 14. A larger left valve. 



Hamilton group. Ontario Co , N. Y 

 Fig. 15. The interior of a left valve. 



Hamilton group. ( ake, .V. )". 



