Maryland (JicoLociicAi, Survey 483 



Description. — " Shell depressed globose. Spire short, little elevated 

 above the body of the shell : volutions three or four, a little depressed at the 

 suture and regularly curving on the top and sides; aperture round or 

 transversely suboval. Surface somewhat lamellose-striate." Hall, 1859. 



This species as found in Maryland is poorly preserved. Only about 

 a half-dozen individuals have come under the notice of the writer, most 

 of them being in the U. S. National Museum and having been identified 

 by Schuchert. 



Occurrence. — Oriskaxy Formation, Eidgely Member. South end 

 of Nicholas Mountain (?). Helderberg Formation, New Scotland 

 Member. Corriganville. 



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



[Ohern.] 



Diaphorostoma desmatum Clarke 



Plate LXXXVI, Figs. 13, 14 



Diaphorostoma desmatum Clarke, 1900, Mem. N. Y. State Mus., voL iii, No. 3, 



p. 29, pL iii, figs. 13-19. 

 Platyostoma desmatum Waller, 1903, Pal. N. J., vol. iii, p. 262, pi. xli.x, fig. 12. 



Description. — The U. S. National Museum has a very small specimen 

 of this species from the Lower Oriskany. The species lacks a definite de- 

 scription ; what has been published being comparisons rather than de- 

 scriptions. The specimen figured was identified by Schuchert. 



Occurrence. — Oriskany Formation, Shriver Member. 21.,t Bridge. 



Collection. — U. S. National Museum. 



[Ohern.] 



Genus PLATYOSTOMA Conrad 



Platyostoma niagauensb Hall 

 Plate LXXXVII, Figs. 3, 4 

 Platyostoma niagarense Hall, 1852, Pal. N. Y., vol. ii, p. 287, pi. Ix, figs. lav. 



Description. — " Globose; volutions three or four; body whorl large, in- 

 flated towards the aperture which is dilated; sutures deep; spire depressed 

 (rarely elevated) ; shell thin; surface striated across the volutions, and in 



