PLATE LXXXI. 



AviCUT,OPECTEN FASCICULATUS. 



Page 11. 

 See Plate 5. 

 Fig. 1. A left v.alve showing the characteristic fasciculate radii. 



Hamilton group. Near Clarksville, Albany Co., N. T. 

 Fig. 2. A left valve with tiner and more regulai- radii. 



Hamilton group. Near Clarksville, N. Y. 

 Fig. 3. The specimen pi. 5, tig. 11, redrawn to show the concentric striae. 



Hamilton group. Castleton, Ontario Co., N. T. 

 Fig. 4. A right valve preserving the radii on the ears and showing the subdued characters of the surface 

 as compared with the left valve. 



Hamilton group. Near Clarksnille, N. Y. 



AVICDLOPECTEN LAUTUS. 



Page 14. 

 See Plate 3. 

 Fig. 5. A figure made from an impression in gutta-percha, from the interior of the specimen illustrated 

 on pi. 3, fig. 17, showing more clearly the surface ornamentation. 

 Hamilton group. York Centre, Livingston Co., N. Y. 



