Gr 
I 
OHIO STATE ACADEMY OF SCIENCE. 
Gomphoceras parallelum, sp. nov. 
(Fig. 2b. Reduced one-half. ) 
Shell rather large, stout, transversly ovate; greatest 
diameter at the upper chamber; 34 inches broad, thickness 
2% inches; length 6 inches. It developed with the three 
first chambers into its width, then running parallel up to 
the shoulders of habitation chamber, when the shell con- 
tracts on each side 4 inch and keep up a parallel neck. 
Chambers 10, the four lowest tapering rapidly into a broad 
dome. 
Habitation chamber large, 3 inches high, of which the 
neck occupies 14 inches. 
Siphuncle not known, nor structure of shell. 
Upper Corniferous limestone, Marion, Ohio. 
Cyrtoceras crescens, sp. nov. 
(Fig. 3. Reduced one-half. ) 
Shell large, nearly circular, of half moon shape: 
circular5 diameter 7% inches, greatest diameter of the 
tube at the 5th air chamber from above, and at the middle 
4% inches. Habitation chamber triangular, the outer line 
sloping cirtularly over to the inner lip; width of base 44 
inches. Air chambers 20; in another specimen the air 
chambers toward the apex are very shallow and presents 
27 of them. !n the specimen before us the apex is lost in 
bie rock: 
Siphuncle nor outer shellmarking could be observed. 
Associated with Gyroceras Ohioensis; G. inelegans in the 
blue limestone of the upper Corniferous group, Devonian. 
Marion, Ohio. 
Cyrtoceras columbiense, sp. nov. 
(Plate VIII. Slightly reduced.) 
Shell-length 74 inches incomplete; central diameter 33 
inches, exogastric curvature # inch, section subcircular, 
chambers 3 to I inch ventrally. Habitation chamber length 
