A Contribution to the Lower Devonian Faunas of Maryland 31 



" The shell is obliquely ovate spreading rapidly from the apex, and be- 

 coming extremely ventricose below • aperture campanulate ; the lip in con- 

 tact with the spire, and sometimes strongly reflexcd. Surface marked by 

 fine transverse or concentric lamellose striae, Avhich are somewhat un- 

 dulated and rarely finely cancellated by faint, revolving striae. Volutions 

 contiguous throughout, or the last one free ; peristome continuous or in- 

 terrupted, free or in contact with the body volutions, sometimes abruptly 

 expanded at the margin." Hall, 1859. 



This variety is made a species by Hall. In the specimens from Mary- 

 land the difl'erence between the typical Platijceras gehhardi and the varietv 

 is so slight that it cannot be regarded as of specific value. Indeed, it is 

 extremely doubtful if even a varietal difi'erence exists and the writer is of 

 the opinion that further collections will show the complete identity of 

 Hall's two species. 



Occurrence. — Oriskany Formation, Eidgely Member. Cumberland, 

 east side iSTicholas Mountain, Hancock. 



Collection. — Maryland Geological Survey. 



Platyceras magnificum Hall 



Plate LXXXII, Figs. 1-6 



Platyceras magnificum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 476, pi. 

 cxix, figs. 1-6, 1861. 



Description. — " Shell obliquely suljovate. Spire depressed below the 

 plane of the outer volution : volutions two or three, very rapidly expanding 

 and becoming extremely ventricose below, usually free or with the first 

 one contiguous; aperture expanded, subcircular, campanulate, and often 

 with the margin reflexed, particularly on the left side. Surface marked 

 by distinct transverse lamellose undulating stria?." Hall, 1859. 



Occurrence. — Oriskany Formation, Eidgely Member. Cumberland, 

 east side Nicholas Mountain, Cash Valley, Maryland; Warren Point, 

 Pennsylvania ; Miller's Spring, West Virginia. 



Collections. — Maryland Geological Survey, U. S. jSTatioual Museum. 



