PLATE XXIII. 

 Leptodesma saviforme. 



>00. 



Si e Plate 22. 

 Pig. 1. A right valve showing the characters of the shell. 



j group . .\ . Y. 



ACTINOFTERIA PERSTRIALIS. 

 LIS. 



See Plat 84. 

 Fig. -2. A left valve. 

 Fig. 7. A right valve of a larger example. 



Chemung gj p. Ithaca, -V. Y. 



ACXIXOPTEKIA DELTA. 



Fig. '■'•■ The left valve described. 



. .Y. Y. 



AcTrXOPTEUIA EPSlLl >\. 



Fig. i. A -mall left i . 



Figs. 5,6. Two left valves rei th some doubt on account of their finer surface radii. 



Fig. 8. An impression ofa left valve, rets li ofthe light valve beneath it in the centre, thus show- 



ing partly tW feature 



I tiemung group. Ithai a, N. Y. 



AcTlNOPTERIA ZETA. 



PL Si. 

 Fig. 9. A light valve showing the form and surface ornamentation, with two oblique lateral teeth. 

 Chemung- group. Ithaca, X. Y. 



Ptyciiopterlj expansa. 



Page l")'.v 

 Fig. in. The left valve desciibed showing and surface ornamentation. The bodj is represented 



as too narrow and there shotild be a slig'W furrow limiting the wing. 

 Fig-. 11. An enlargement of i xior umbonal slope, showing the direction of the radii. 



Chemung group. $wethi 



Ptych&opteria Proto. 



[29. 

 i igs. L2, 14. Two left valves. The wings in each one should be limited by a slight furrow. 

 Chemia j s ip. Near Smettoport, Pa. 



