286 Systematic Palkoxtology — Middle Devoxiax 



Bellerophon leda Hall, 1S79, Pal. N. Y., vol. v, pt. ii, p. 110, pi. xxiii, figs. 2-16. 

 Bucanopsis leda Ulrich and Scofleld, 1897, Geol. Minn., vol. iii, pt. ii, p. 854. 

 Bellerophon leda Clarke, 1903, N. Y. State Miis., Bull. G5, p. 524. 

 Bellerophon (Bucanopsis) leda Clark and Mathews, 1906, Md. Geol. Surv., 



vol. vi, pi. xvii, fig. 12. 

 Bucanopsis leda Grabau and Sliimer, 1909, N. Am. Index Fossils, vol. i, p. 



623, fig. 837. 



Description. — " Shell subglobose, often a little flattened upon the dor- 

 sum; body-whorl ventricose, very rapidly expanding; aperture very wide; 

 peristome abruptly spreading, broadly sinuate in front and sometimes 

 with a deeper notch in the middle, the margin joining the volution a 

 little on the ventral side, where it is thickened, somewhat abruptly curv- 

 ing over and partially enclosing the small umbilicus. Surface marked 

 by strong longitudinal or revolving striae, which alternate in size, are 

 sometimes fasciculate, and often finer and more numerous on each side 

 of the dorsal band than on the lateral portions of the shell; the revolving 

 striae are cancellated by finer, subequal, thread-like transverse striae ; the 

 dorsal band is narrow, rarely elevated or sometimes scarcely raised above 

 the surface, and usually flat or slightly concave, the concentric striae 

 making an abrupt retral curve upon it in crossing." Hall, 1879. 



A broken specimen of this species was found in the thin argillaceous 

 shales of Evitts Creek below Wolfe Mill. Although it is a very imper- 

 fect specimen, still on account of the well preserved highly characteristic 

 surface markings it is thought that there is no doubt regarding its identi- 

 fication. The ventricose and expanded body-whorl ; alternating revolv- 

 ing striae, cancellated by transverse ones; and flat dorsal band upon 

 which the transverse striae make an abrupt retral curve are clearly shown 

 and very distinctive characters. 



Lengtli of imperfect specimen, 20 mm.; width, near front margin, 

 26 mm. 



Occurrence. — Eomney Formation, Hamilton Member. East bank 

 Evitts Creek below Wolfe Mill. 



Collections.— ^laryland Geological Survey; Xew York State Museum: 

 American ]\Iuseum of Xatural Historv. 



