PLATE LXXXYII. 



Glyptodesma erectum. 



See Plates 11, 12, 13, 25 and 86. 

 Fig-. 1. The interior of a specimen -nath the valves thrown open, showing the comparative size and foi-m 

 of the valves, the hinge characters and muscular markings. 

 Hamilton group. BelpM, Onondaga Co., iV. ¥. 

 Fig. 2. The internal mould of a left valve, showing the pallial line, muscular impression and small tuliei-- 

 cles in the inter-pallial area, I'epresenting the points of attachment of small umbonal muscles. 

 Hamilton group. Pratt'x falls, Onondaga Co.. jK. Y. 

 Fig. 3. An internal mould of a right valve showing the anterior and posterior adductor muscular impres- 

 sions, and a small Crania atfaclied to the wing. 



Hamilton group. Pi-om a boulder,. J-Yaverly, Tioga Co., N. Y. 



..<M. ,^^^^^vll .'jc, 

 PaL,EOPINNA rLABELT,A. 

 Page 2)0. 

 See Plate 25. 

 Fig. 4. The left valve described, showing the form of the shell and a single groove along the hinge. 

 Oriskany sandstone. Schoharie, N. Y. . , ^ ■sviif/ ii'.i A 



PtERONITES IXOl'TATUS. 

 Page 239. 

 Fig. 5. A left valve showing the form of the shell. The scar on the post-umV)onal slope was produced by 

 the attachment of a Crania. 



Chemung group. Mamifidd, Pa. 



