PLATE LXXXVII. 
Glyptodesma erectum. 
Page 153. 
See Plates 11,12, 13, 25 and 86^ 
Fig. 1. The interior of a specimen with the valves thrown open, showing the comparative size and form 
of the valves, the hinge characters and muscular markings. 
Hamilton group. Delphi, Onondaga Co., N. Y. 
Fig. 2. The internal mould of a left valve, showing- the pallial line, muscular impression and small tuber¬ 
cles in the inter-pallial area, representing the points of attachment of small umbonal muscles. 
Hamilton group. Pratt's falls, Onondaga Co., N. Y. 
Fig. 3. An internal mould of a right valve showing the anterior and posterior, adductor muscular impres¬ 
sions, and a small Crania attached to the wing. 
Hamilton group. Prom a boulder, Waverly, Tioga Co., N. Y. 
PaL/EOPINNA flabelea. 
Page 240. 
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. 
Pteronites inoptatus. 
Page 239. 
Fig. 5. A left valve showing the form of the shell. The scar on the post-umbonal slope was produced by 
the attachment of a Crania. 
Chemung group. Mansfield, Pa. 
