480 Systematic Paleoxtology 



closely involved, the last one free, somewhat rapidly expanding, flattened 

 upon the back and becoming ventricose towards the aperture : aperture 

 rounded or broad oval. Surface marked by strong transverse or slightly 

 oblique nodes or ridges upon the dorso-lateral angles of the last volution, 

 about eleven or twelve on each side, which are sometimes connected by a 

 low ridge across the back (the two upper volutions being rounded and free 

 from such ridges). Entire surface marked by regular even thread-like 

 longitudinal striae." Hall, 1859. 



A single individual of this species has been found in the state. Of its 

 identity there is little if any doubt, but, as seen in the specimen figured, 

 the transverse ridges are very oblique, due, in part at least, to distortion. 



Height 1.5 cm. ; diameter of aperture 2.3 cm. 



Occurrence. — Oriskany Formation, Eidgely j\Iember. Warren 

 Point, Pennsylvania. 



Collection. — Maryland Geological Survey. 



[Ohern.] 

 Genus STROPHOSTYLUS Hall 



Strophostylds transversus Hall 

 Plate LXXXVI, Figs. 5-7 



Strophostylus transversus Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 470, 

 pi. cxiv, figs, la, &, c, 1861. 



Description. — " Shell obliquely ovate, symmetrical. Spire little ele- 

 vated: volutions about four, the last one extremely ventricose and very 

 much extended on the margin; aperture subcircular ; outer lip very thin, 

 curving downwards and spreading over the surface of the adjacent volu- 

 tion. CoUumellse lip spirally grooved: suture canaliculate. Surface 

 finely striated in direction parallel to the lines of growth, with a few more 

 strongly marked imbricating lines of growth." Hall, 1859. 



Length 3.75 cm. ; maximum diameter 4.5 cm. 



Occurrence. — Oriskany Forimation, Eidgely Member. Cumberland 

 (fide Hall). 



Collection. — American Museum of Xatural History. 



[Ohern.] 



