PLATE LXXXI-Contlnuert. 



A VICULOPECTEN TEND! 8. 



Page 39. 



See Plate 7. 



Fig. 6. The left valve represented on pi. 7, tig. 23, redrawn to show the true form and ornamentation, 

 with the pallial line and muscular impression. 



Chemung- group. JVmr Salamcmra, iV. Y. 



AviCULOPECTEX INSIGNIS. 

 Page 34. 



See Plates I a 

 Fig'. 7. A left valve preserving the form and proportions in greater perfection than shown on the previous 

 plates. Hamilton group. Stafford, Genesee Co., N. T. 



AVICULOPECTEN BELLUS. 

 Page 35. 



See Plate 3. 

 Fig. 8. A right valve, X 2. 



AviCULOPECTEX DUPLICATUS. 

 Pagel7. 

 See Plate 7. 

 Fig. 9. A left valve showing the coar on the pallial margin. 



Chemung group. Mansfield, Pa. 

 Fig. 10. An entire right \ ah e, 



Chemung group. Mansfield, Pa. 



A VICULOPECTEX KUG.ESTRIATUS. 



Page 15. 



See Plate 7. 



Pig. II. A right valve preserving the surf* haracters with considerable perfection,, 



( Ihemung gronp. B PT. 1". 



Fig. 12. Several of the radii, of the preceding specimen, enlarged two diameteffl '" Bhow the changes in 

 surface ornamentation from the beak to the b; 



AviCULOPECTEX PRINCEPS. 

 Page I. 

 See Plat d 24. 



A right \ ah e Bhowing the pallial line and muscular impression. 

 Hamilton group. T/udlowmUe, N. Y. 



A bj imen with a portion of the l>-t't valve removed showing the interior of the rfghl valve and 



Hi in >i/.- between the right and left valves. 



Hamilton group. Mull. Co., X. T. 



A left valve as preserved in limes 



Hamilton group. /< . Ohio. 



men preserved in a soft shale showing i trie strife. 



Iton group. Livingston Co., X. Y. 

 An individual vertically imbedded in the shales showing the effects of compression and distortion, 

 Hamilton group. X. Y. 



