ri.ATK \.\rv— Contiimcil. 



Pterinea (Veutumxia) reveksa. 



Page 104. 

 See Plate 84. 

 Fig. t>. A large right valve. Another figure of this specimen is given on plate 84, fig. 24, to show the 

 ob.solescence of the rays on the wing. 



Chemung group. Elmira, N. Y. 

 Fig. 12. A specimen with the valves united along the hinge, showing the convex right valvo and flat or 

 concave left valve. 



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



AVICCLOPECTEN PRINCEPS. 



I'agc 1. 

 See Plates!, f>, 6 an.l SI. 

 Fig. 7. An enlargement, to two diameters, of the impres.sion of the hinge, showing the striations of the 

 , liganient.al area. 



Hamilton grouj). Cazetinrin, iV. Y. 



I.,VI!IOPECTEN CYJIIl.VLON. 

 Page 47. 

 Fig. 8. A large, perfect left valve. The specimen shows a striated ligamental area. 

 Hamilton group. Prom a boulder near Elmira, N. Y. 



Ptekinea (Vertumnia) avis. 



P.nge lie. 

 Fig. 9. An imperfect right valve. 



Chemung group. Near Elmira, JV. Y. 

 Fig. II. A large, convex right valve. The figure should be restored at the cardinal angles to correspond 

 with fig. 13. 



Chemung group. Mansfield, Pa. ' ; n ' .' 

 Fig. 13. A nearly entire left valve. The liyssal sinus should be a little deeper than is represented. 

 Chemung group. Near Elmira, N. Y. 



Pterinopecten suborbiculauis. 



Page SO. 

 See Plates 8 and 82. 

 Fig. 10. A view of a large and very perfect left valve. The radii increase by intwstitial addition and not 

 by bifurcation as is represented in the figure. 



Chemung group. Elm Vnlliij, Alleghany Co.. N. Y. 



LiMOPTERA MACROPTERA. 



Page 246. 

 .See Plates 26, 27, 28, 29 and 92. 

 Fig. 14. A small right valve showing the form and surface ornamentation. 

 Hamilton group. Pratt's Fall.i, Onondaga Co., N. Y. 



Allocardium alternatum, gen. et sp. nov. 



Fig. 1.5. A view of the spec-men enlarged to two diametei-s. The relations of this shell are not apparent. 

 It has the a-spect of a bivalve shell in the charactei-s of the rays and the cardinal aurionlation, 

 and somewhat resemliles Hii'i'Aui's and Trigoniluna. With the present materi.al it cannot 

 be satisfactorily arranged with any known genus of molluscs. 

 Hamilton group. Cayuga lake, N. Y. 



