462 PROCEEDINGS OP THE ACADEMY OP 



rather narrow, concave, and located above the narrowly rounded periphery of 

 the body whorl, passing around rather below the middle of the other volutions. 

 Surface ornamented by from about seventeen to twenty-two revolving lines, 

 only three or four of which occupy that part of the body whorl above the 

 band, where they are larger and more widely separated than below; distinct, 

 but much smaller, regularly arranged, thread-like lines mark the volutions 

 transversely. 



Length and breadth each about 0-22 inch; apical angle convex, divergence 79. 



Locality and position. Hodges Creek, Macoupen County, Illinois. Coal 

 Measures. 



Pleurotomaria Shumardi. Shell trochiform, of medium size, very thin ; spire 

 moderately elevated, conical, pointed at the apex. Volutions about six, 

 increasing rather rapidly in size, obliquely flattened above ; those of the spire 

 being somewhat angular near the lower side; last one very prominent, and 

 angular around the middle, the immediate edge of the angle being terminated 

 by the narrow spiral band, convex below. Band slightly concave, and 

 margined above and below by a small line or indistinct angle, the lower one 

 of which scarcely rises above the suture on the upper whorls. Suture well 

 defined. Umbilicus small, or nearly closed. Aperture rhombic subquad- 

 rangular, wider than high. Surface ornamented by numerous transverse lines, 

 which are very regular and closely arranged on the upper whorls, but become 

 stronger, more distinct, and less regular on the last turn. In crossing the 

 upper flattened sloping sides of the whorls, these lines arch a little forward, 

 and pass very obliquely backwards from the suture to the band; on the under 

 side of the body whorl they are small, nearly obsolete, and crossed by obscure 

 traces of fine revolving strife. 



Named in honor of Dr. B. F. Shumard, State Geologist of Texas. 



Length 0-70 inch; breadth 0-73 inch: apical angle rather distinctly concave, 

 divergence 70 



Locality and position. Warsaw and Keokuk, Illinois. Base Geode bed, 

 Warsaw Limestone, of Lower Carboniferous series. 



Genus STRAP AROLLUS, Montfort?=ETJOMPHALUS, Sowerby. 



Euomphalus planodorsatus. Shell of medium size, subdiscoidal, spire nearly 

 fiat, or but slightly elevated above the body whorl. Volutions about five, 

 increasing gradually in size from within, flat above, and provided with a 

 moderately distinct revolving angle about two-thirds of the distance across 

 from the inside; from this angle the outer whorl is rounded over the periphery 

 to about the middle of the under side, where there is another angle, from 

 which it rounds into the umbilicus ; suture well defined. Umbilicus large, 

 deep and showing about one-half of each inner whorl ; aperture subcircular. 

 (Surface unknown.) Height about 0-30 inch ; breadth 1 inch. 



Allied to E. pentangulatus, Sowerby, but differs in having the angle on the 

 upper side of the whorls located nearer the outer margin, and the periphery or 

 outer side of its volutions more broadly rounded. 



Locality and position. Thompson's quarry, Randolph County, Illinois. Chester 

 Limestone, of Lower Carboniferous series. 



Euomphalus umbilicatus. Shell of medium size, depressed subtrochiform ; 

 spire rather elevated for a species of this genus. Volutions five to five and 

 a-half, convex, increasing gradually in size, nearly horizontally flattened on 

 the upper side, about half-way across from the suture, where there is a 

 rather distinct revolving angle, below this angle the upper oblique outer 

 slope is slightly flattened to near the middle of the outer side, which, in the 

 last whorl, is narrowly rounded ; under side of body volution rounded to a 

 moderately distinct angle near the middle, thence rounding into the umbilicus. 

 Suture well defined. Umbilicus large, or nearly twice as wide as the diameter 



[Oct. 



