'i; ^-.-V*--' 



■,-£f r 



PLATE LXV. '^^^ 



Sphenotus tklncatus. 



I'age 3!M. 

 Fig. 1. A small right valve. 



Hamilton group. Schofiarie Oo.. N. Y. 

 Vig. 4. A BpeciiniMi pre.serving both valves. ^ . 



Hamilton group, i^chohane Co , N. Y. 

 FifT. T). A Bmnlli^r imlividual enlarged to two (liamctors. 



Hamilton group. Shore of Skiuneal4)l§ii Jake, N. Y. 

 Fig. 6. A left valve showing unusually strong concenti-ic nndulatitjuB. 



Hamilton group. Schoharie ''n., y. Y. it, mjilin 



OkTHONOIA ? I'AKVUtA. 



I'ase 48-i. 



See Plfttp 78. 

 Figs. 2, 3. Left anil right valves. The fold on the post-cardinal slope is too stfoj^gly r^pjsesented. 



Sphenotus arc^;koumis. 



^ :P»g« 3B5, , ,/ ;| . - 



See PH,te 66. 

 Fi^s. 7-10. Four right valves showing some vai-iation in fonn and pi-ojwrtSons. 

 Fig. 11. A left valve. ' 



Hamilton group. Delphi, N. Y. 



8PHENOTU3 CrONBATUS. : lijH sdT 



Page'.'fiW. 



Figs. I2-H. Three valves jjrcsentiiig the usual charactei-e of tlii.s sjn-cii-s. 



UauUltou gi-ouj). SiJwharie Co., N. Y. 

 Fig. 1."). The right sidt; of a small specimen retaining the valvi-s in conjimction. 



Hamilton group. Schoharie Co., N. Y. 

 Fig. 1 6. A large right valve. 



Hamilton group. Schoharie Co , N. Y. 

 Fig. 17. A large sjM'i-imen with the valves (tonjoined. 



Hamilton group. Schoharie Co., N. Y. 



