^Maryland Geoi.oijicai. Siuvkv G6.") 



but is a more slemler shell with iiiotl' jiroiiiiiu'iitly (iiitslandiiiii- wlini'Is. 

 \Yher(' fniind in tlie sandstones it is very aliuinlaiil. 



Ocnin-cncc. — Jknnings FoiaiATiox, CuK-Mixc !\lE.AiBi:ii. In loose 

 blocks of yellow sandstone with PaUcoiroclnis jinrrnrsor, near Deei' I'ai'k 

 Station, and in place near Trout Kun, 'I miles south of Oakland. 

 Parkhead Member. Also in olive shales near the base of the seetion 

 on the west slope of Polish Mountain. 



C'o//ec^^o/^— Maryland Geological Survey. 



Family BELLEROPHONTIDAE 



Genus BELLEROPHON Montfort 



Belleropiion nactoides n. s]). 



Plate LXVII, Figs. 1:5-] (5 



Description. — Shell of mciljinn dimensions for this genus, much en- 

 rolled with aperture but slightly expanding. Whorls full and rounded 

 but luirrow. Peripheral seam distinguishable over the entire exi)osed 

 wlioi'l and becoming v<'ry prominent over the last half or two-thirds 

 volution where it is abruplly and sharply elevated. The surface at either 

 side of the keel-like seam is noticeably depressed into revolving grooves. 

 Aperture deeply and sharply enuirginate at the seam, the sides bending 

 outward in a broad curve. Surface of the shell marked by concentric 

 stria^ which become rugose near the aperture and are there interspersed 

 witli sparsely scattered pustules. 



Diameter of shell !•") mm. : width of aperture 13 mm. 

 - This shell is characterized liy its cariniform seam and revolving de- 

 pressions as well as by the tubercular ornamentation of its apertural 

 region. Tt is a true Bellcrn/ihon and has so much tlie general aspect of 

 the Xew York Chemung species />'. iiaclas (see Pal. X. Y., vol. v. pt. ii, 

 p. 1"21. pi. x.wi, figs. 17, IS) that it is given the above desig-natiou. 

 The sparse pustules of the surface suggest the ornauu-ut of the Chemung 

 species B. mcera Hall {idem. pi. xxv, tigs. 9-14 ; pi. xxvi, tigs. 19-23). 



Occurrence. — Jennings Formation, AVoodmont Member, Ithaca 

 Fadna. On the road west of Tonoloway Hill, Allegany Countv. 



Collection. — Marvland Geological Survev. 



