GASTEROPODS. 141 



Pleurotomaria sphaerulata CONRAD. 



Pleurotomaria sphcerulata Conrad, 1842: Jour. Acad. Nat. Sci , Phila., vol. 



VIII, p. 272, pi. xvi, fig. ]2. 

 Pleurotomaria coronula Ball, 1852: Stanbury'8 Exped. Gt. Salt Lake, p. 413, 



pi. iv, figs. 4f, 6a-d. 

 Pleurotomaria. sphaerulata Hall, 1858: Geology Iowa, vol. I, p. 722, pi. 



xxix, fig. 13. 

 Pleurotomaria sphnerulata White, 1884: Geol. Sur. Indiana, 13th. Ann. 



Rep , pt. ii, p. lil, pi. xxxii, figs. 152 and 153. 

 Pleurotomaria sphcerulata Kejes, 1891: Proc. Acad. Nat. Sci., Phila., p. 



253. 

 Pleurotomaria sphcerulata Keyes, 1891 : Johns Hopkins Univ. Circulars, vol. 



XI, p. 29. 



Shell of medium size, subturbinate ; spire more or less 

 depressed, with nearly straight sides; volutions about six in 

 number, rather sharply rounded at the periphery ; outer lip 

 with a broad and deep notch. Surface glabrate, except along 

 the suture, where there is a single row of rather conspicuous 

 tubercles ; a few indistinct lines of growth are also often dis- 

 cernible. 



Horizon and localities Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Pleurotomaria grayvillensis NORWOOD & PRATTEN. 

 Pleurotomaria grayvillensis Norwood and Pratten, 1855 : Jour. Acad. Nat. 



Sci., Phila., vol. Ill, p. 75, pi. ix, fig. 7. 

 Pleurotomaria grayvillensis Geinitz, 1866: Garb, nnd Dyas in Nebraska, 



p. 9, tab. i, fig. 9. 

 Pleurotomaria grayvillensis Meek, 1872: U. S. Geol. Sur. Nebraska, p. 233, 



pi xi, fig. 9. 



Pleurotomaria grayvillensis Keyes, 1888: Proc. Acad. Nat. Sci., Phila., 

 ' p. 238. 



Shell rather small, conical, subovate, longer than wide ; 

 spire moderately elevated ; volutions five to seven, obliquely 

 flattened above. Body-whorl large, rapidly increasing in size, 

 rounded below ; biangular around the periphery, both angles 

 being visible on the spire. Aperture subrhombic ; outer mar- 

 gin sharp. Columella somewhat extended below. Surface 

 ornamented by from 25 to 40 revolving lines, of which 20 or 

 more occupy the inferior surface of the last turn ; some of the 



