PLATE LXXXVI. 
Glyptodesma erectum. 
, Page 153. 
See Plates 11, 12, 13, 25 and 87. 
Fig. 1. A left valve of a small individual. 
Hamilton group. Fabius, Onondaga Co., N. Y. 
Fig. 2. The right valve, as seen lying within the left, showing its form and comparative size. 
Hamilton group. Cayuga lake, iV. Y. 
Fig'. 3. The hinge of a specimen, showing the striated ligamental area and strong cardinal folds. 
Hamilton group. Delphi, Onondaga Co., N. Y. 
Fig. 4. A small left valve with small anterior wing and very large posterior wing, also showing one-of the 
oblique lateral teeth. 
Hamilton group. Cayuga lake, N. Y. 
Fig - . 5. The anterior profile view of a very perfect specimen retaining the test, showing the comparative 
convexity of the valves. 
Hamilton group. Pratt's falls, Onondaga Co., IV. Y. 
Fig. 6. The left valve fig. 8, plate 11, redrawn to show the ligamental area, lateral teeth and muscular 
impression. The tubular markings around the margin are the remains of the excavations 
made by boring sponges. 
Hamilton group. Cazenovia, IV. Y. 
Fig. 7. A large right valve, showing the ligamental area, pallial line, muscular impression and umbonal pits. 
Hamilton group. Gilbertsville, Otsego Co., N. Y. 
Fig. 8. A left valve presenting the same internal characters as the preceding, together with two strong 
lateral teeth. 
Hamilton group. Albany Co., N. Y. 
Glyptodesma occidentale. 
Page 157. 
See Plate 15. 
Fig. 9. The specimen of fig. 12, plate 15,. redrawn to show the erect form of the body and extent of the 
posterior cardinal expansion. 
• Upper Helderberg group. Falls of the Ohio. 
