GEOLOGY OF THE FOURTH DISTRICT. 
ORGANIC REMAINS OF THE CHEMUNG GROUP. 
No. 63. — No. 122, page 269. 
Figs. 1 and 1 a. Delthyris mesastrialis, H. Cayuta creek. 
Fig. 2. Delthyris mesacostalis, II. Angelica. 
Fig. 3. Delthyris disjuncta? Phillips (Palaeozoic fossils, pi. 29, fig. 128, f. g. h., and 129, 
pi. 30, fig. 129). Chemung. 
No. 64. — No. 123, page 270. 
Fig. 1 . Delthyris cuspidata, H. This fossil resembles some of the varieties of Spirifera 
disjuncta. (Sowerby, Geol. Trans. 2d series, Vol. 5, pi. 54, figs. 12, 13; pi. 55, 
fig. 2 ; also Pal. fossils as quoted above.) Cayuta creek. 
Fig. 2. Delthyns acanthota, H. Upper and lower valves. Chemung. 
Fig. 3. Delthyris mucronata ? (See fossils of Hamilton group.) This is the only specimen 
resembling this fossil seen in the Chemung group. 
Figs. 4 and 4 a. Delthyris inermis, H. Twenty-mile creek, Chautauque county. 
Fig. 5. Delthyris acuminata, H. 5 and 5 a. Internal casts of the shell. 5 b. Enlarged 
portion of a cast of the external surface. Ithaca. 
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