475 



[Newell. 



men above figured was probably full grown as the septa adjacent 

 to the living chamber are nearer together than those of younger 

 age. The siphon has not been found, and the test and surface 

 markings are unknown. The type specimen as illustrated is some- 

 what distorted, especially about the dorsal aperture. The dimen- 

 sions of this shell are : total length from smallest chamber to dorsal 

 opening 115 mm. ; greatest dorsi- ventral diameter taken just below 

 projection of apertures 88mm. ; transverse diameter, somewhat 

 compressed, 45 mm. ; height of living chamber 58 mm. 

 Locality. — Bridges Quarry, Wabash, Ind. 



GOMPHOCERAS ANGUSTUM n. Sp. 



Vertical and lateral views. X h 



Compare Gomphoceras (Phragmoceras) ellipticum H. & W., Pal. Ohio, n, p. 



152, pi. 8, fig. 11. 

 Compare Gomphoceras (Phragmoceras) imbricatum Barr., Syst. Sil., n, pi. 



46. 



Shell large, arcuate ; transverse section narrowly elliptical ; the 

 dorsi-ventral diameter uniformly increasing from the smallest closed 

 chamber up to the aperture. The ventral or concave side is suban- 

 gular, the dorsal narrowly rounding. The apex is unknown. 



The living chamber is large with a length at least a third greater 



