GEOLOGY OF THE FOURTH DISTRICT. 
ORGANIC REMAINS OF THE HAMILTON GROUP. 
No. 47. — No. 85, page 207. 
Fig. 1. Deltliyris granulifera. 
Fig. 1 a. End view of the same, showing the spiral coil within the shell. Pavilion, Genesee 
county. 
Fig. 1 b. A specimen with a more extended hinge line. Moscow. 
Figs. 1 c and 1 d. A younger shell of the same species. Pavilion. 
Figs. 2 and 2 a. Deltliyris congesta, H. Seneca lake shore. 
Fig. 3. Deltliyris mucronata, H. View of the hinge. 
Fig. 3 a. Area of lower valve. 
Fig. 3 b. Lower valve. Moscow. 
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