PLATE II. 

 Lyriopecten interkadiatus. 



Page U. 

 See Plate 82. 

 Fiir. 1. A small loft valvp. 

 Fifr. 2. A .'ipocimoii nf mpdiiim size. 



Fiy. S. Th<,' i-ifrht valvp ticlonfriiif; to thi- l«ft valvp. tig-. 1. 

 KifT. 4. The right valve nf tiff. 2. 



Hamilton gTuup. Piiltonham, fichoharieCo.. N. Y. 



AviCL'LOPECTEN BELLCS. 

 Page 36. 

 See Plate 81. 

 Fi}.'. .1. A .-(mail left valve. X 2. 

 Fijj. K. A similar left valve, X 2. 



Fig-. ;». A .ipHi-iiiiHii ))reserviiifr I'oth valves, showing their i-om|iavalive form and relations, X i- 

 Hamilton jrrouii. Xear Belloiia, N. Y. 



AviCULOPECTEN ORNATUS. 



Page .37. 



See Plate 3. 



Fifr. 7. A small .speiiinen piv.serviiifr liolh valves sligrhtly (lisplactcil, and the right one imperfect : 



showinfT the form and ornamentation, X ''■ 

 Fijr. 8. .\ larger specimen, similai- to the iirecediiig, bnt with the sui-faee charactei'S partially obliterateil 

 from maceration, X -■ 



Hamilton gronp. Caviiiid-aifftta hike. X. Y. 



l^TERINOPECTEN UXDOSUS. 

 I'age 72. 

 .See Plate S2. 

 Fig. 10. A small Ifft valvi-, showing tlic! great proportional length of hinge-line in the young .shell. 



Hamilton group. Cuitaiidaigua lake. N. Y. 

 Fig. U. A large left valve, U;iviiig very distant eipial radii. 



Hiimilton gi'ouj). Bethany, N. Y. 

 I"'ig. 12. A i-ight valvi', showing numerous concentric undulations. 



Hamilton group. CaiuiiKlaigua lake. N. Y. 

 Fig. i:-!. .\ right valve preserving two strong undulations in the nndioinil regimi, nior.' snliducd concentric 

 lines l>elow, and numerous tine radii. 



Corniferous limestone. Claniice HuUmc, xV. Y. 

 Fig. H. A right valve preserving a jiortion of the test on the upper anterior side and jinterior ear. 



Hamilton gronp. 1'aiiandaiyim lake, N. Y. 

 Fig. l.T. .\ characteristii' right valve. 

 Fig. Hi. .K large nght valve, showing numerous concentric undulations. 



Hamilton group. CaHandaigiM lake, N. Y. 

 Fig. 17. A small specimen preserving both valves and showing strong undulations. 



Hamilton group. Caitaiidatyna lake. jY. Y. 

 Figs. IS. 19. Two nearly entire large left valves. 



Hamilton gj-oup. Oeneseo. TAvingston Co.. N. Y. 



