PLATE LXXXII. 



AviCULOPECTEX iEQUILATERALlS. 

 Page 19. 

 Fig 1. A left valve showing the form and surface ornamentation. 



Chemung group. Alleghany Springs, Warren Co., Pa. 



Lyriopectex AXoMLEFORMIS. 

 Page 53. 

 See Plates 4 and 10. 

 Fig. 2. The specimen illustrated on plate 10, fig. 5. redrawn to show the proper form and surface orna- 

 mentation. 



Chemung group. Chemung creek, N. Y. 



Lyriopectex orbicularis. 



Page 42. 

 See Plate 4. 

 Fig. 3. A specimen with the upper portion of the left valve removed, showing the exterior impression of 

 the right valve and the comparative size of the two valves. 

 Hamilton group. G j»a lake. JV. Y. 



Pterixopectex SUBORBICULAKIS. 

 Page 80. 

 See Plates 8 and 24. 

 Fig. 4. A right valve of this species showing the deep byssal sinus. 

 Chemung group. Mansfield, Pa. 



Lyriopectex ixtereadiatus. 



Page 44. 

 See Plate 2. 

 Fig. 5. A large left valve showing the surface ornamentation and the ligaments! area. 

 Hamilton group. SchoharU ('<>., iff. Y. 



Lyriopectex Priamus. 



Page 54. 



Plate 10. 

 Fig. 6. A right valve of this species. 



Chemung group. FrankliA, Delaware Co., iff. Y. 



Pterixopectex uxdosus. 



Page 72. 

 See Plate 2. 

 Fig. 7. A left valve with comparatively few radii, and the strong characteristic concentric undulations. 

 Hamilton group. Bethany, iff. Y. 



Ptekixopectex keflexus. 



Page 58. 

 Fig. 8. A view of the interior of a left valve. 



Corniferous limestone. Ohio fells. 



