458 PROCEEDINGS OP THE ACADEMY OF 



Genus CARDIOMORPHA, Koninck. 



C ardiomorph a radiata. Shell subcircular, gibbous in the central and umbonal 

 regions, base more narrowly rounded than the front or anal margin ; cardinal 

 border a little arched ; beaks gibbous, abruptly pointed, incurved and showing 

 a tendency to curve forward at the immediate points, depressed or rising 

 but little above the hinge margin ; surface ornamented by numerous fine, 

 regular, radiating, rather rounded striae, about equalling the depressions 

 between. (Hinge and interior unknown.) 



Allied to C. ovata of Hall, (Rept. Survey Iowa, pi. 7, fig. 10), from near the 

 same horizon, but more rounded in outline, and has much less elevated 

 and less curved beaks. Both these species differ from the typical forms of Cardio- 

 ?norpha, Koninck, in having radiating strife, and may prove to be generically 

 distinct when specimens showing the hinge and interior are obtained. 



Length 0-95 inch ; height 1 inch ; breadth or convexity 0'77 inch. 



Locality and position. Rockford, Indiana. From beds containing Carbon- 

 iferous species of Goniatites, but generally supposed to be of Upper Divonian 

 age. 



GASTEROPODA. 



Genus BELLEROPHON, Montfort. 



Bellerophon crassds. Shell large, very thick, subglobose, or a little longer 

 than wide ; volutions expanding somewhat rapidly, rounded over the dorsum 

 and sides ; umbilical region excavated, but not perforate ; mesial band narrow, 

 rather prominent, and margined on each side by a raised line ; aperture 

 transverse, reniform, or sublunate ; lip strongly thickened near the umbilical 

 excavations on each side, but not covering them, thinner and but slightly 

 prominent on either side of the narrow sinus in its outer margin, and spreading 

 in the form of a moderately thick, smooth, callus, over the inner whorls 

 within the aperture, and between the callosities on each side ; surface marked 

 by rather distinct irregular wrinkles, and lines of growth, the former of which 

 are strongest on each side near the lip. 



Greatest length 2-20 inches ; breadth at the aperture 2 inches ; breadth of 

 the mesial band near the aperture 0'12 inch. 



Locality and position. Pittsburg, St. Claire County, Illinois. Lower part 

 of the Coal measures. 



Genus PLEUROTOMARIA, Defrance. 





Pleurotomaria subconstricta. Shell small, conical subovate, longer than 

 wide ; spire moderately elevated, rather pointed at the apex. Volutions five 

 and a-haif to six, obliquely flattened or concave above, excepting near the 

 suture, where there is a subangular prominence occupied by a series of small 

 nodes or granules ; those of the spire having a second angle a little below 

 the middle. Body whorl forming rather more than half the entire length, 

 biangular around the middle, the lower angle being less prominent and more 

 obtuse than the other, and not exposed on the spire ; vertically flattened or 

 a little concave on the outer side, and convex below. Suture linear, but 

 occupying a rather distinct rounded constriction or depression. Aperture 

 broad subovate, approaching a rhombic subquadrate outline ; columella not 

 distinctly perforate. Surface ornamented by about fifteen revolving lines, 

 some ten or twelve of which occupy the under side of the body whorl, where 

 they are larger than on any other part of the shell ; crossing these there are 

 very fine transverse strife, which are closely arranged on the upper slope of 

 the whorls, particularly in crossing the spiral band, but on reaching the lower 

 angle of the body whorl, they become stronger, so as to give it a crenulated 

 appearance. Spiral band narrow, fiat and located just above the middle angle 

 of the body volution. 



[Oct. 



