PLATE XVI. 

 Pterinea consimilis. 



Page luu. 

 See Plate 84. 

 Fig. 1. A small right valve, showing- the strong- radii on the wing ami their absence over the body. 

 Fig. 2. A larger right valve, imperfect at the posterior margin. 

 1'i. 8. An imperfect left valve, showing a very broad striated ligamental area. 



Chemung group. Near Elmira. N. Y. 

 Fig. 9. A similar left valve of somewhat shorter form. 



Chemung group. Near Elmira, N. Y. 

 Pig." 11. A left valve, showing some irregularity in the concentric markings of the shell along the ven- 

 tral margin : probablj due to a natural irregularity in the growth of the shell. 

 Chemung group. Near Elmira. JV. Y. 



Pterinea Chemungensis. 



Page 98. 

 See Plate 84. 

 Pig. 3. .A right valve, showing the term and surface ornamentation. 



Chemung- group. Chemung river. Vppi r yarrows, N. Y. 

 Figs. 7, 10. Two left valves of very erect form. 



Chemung group. Chemung Narrows, N. Y. 

 Fig. 12. A left valve, more oblique than the preceding. 



Chemung group. Chemung river, Upper Narrows, N. Y. 



Pterinea prora. 



Page 102. 

 4. An imperfect right valve. The specimen shows the pallia! line and muscular scar. 

 Chemung group. Near Elmira, N. Y. 

 Pig. L3. The right side Of a specimen preserving a part of the right valve lying in the impression of 

 ili.- left one. 



Chemung group. Near Elmira, N. Y. 

 Pig. II. An impression of a right valve, retaining a portion of the left valve around the pallial margins. 



Pterinea rigida. 



Page 101. 



Pigs.fi>, 6. Two left valves, showing- the characteristic form and ornamental] f lie- sj ies. 



Chemung group. Chemung Co., N. P.' 



