112 PALAEONTOLOGY OF ILLINOIS. 



GENUS CONOCARDIUM. Bronn. 



CONOOARDIUM PARRISHI. (sp. DOV.) 

 PI. XX, Fig. 7. 



Shell obliquely triangular, hinge line straight, beaks depressed 

 umbonal ridge elevated into a strong rounded fold with faint 

 traces of fine striae towards the lower extremity. Anterior side 

 evenly and rapidly sloping from the umbonal fold to the ex- 

 tremity, and traversed by radiating costae only four or five of 

 which extend to the hinge line, but increasing by division and 

 implantation so that ten or more may be counted on the mar- 

 gin of the shell, the one nearest the umbonal ridge being some- 

 what stronger than the others. 



Posterior side flattened towards the extremity, and marked 

 by eight or more flattened striae nearly all of which extend to 

 the hinge line. 



Length about 5 /i inch. 



Position and locality: Oolitic limestone of the upper Coal 

 Measures near Kansas City, Mo. 



Collector, W. J. Parrish, of Leavenworth, Kansas, to whom 

 we have dedicated the species. 



No. 2605 of the Illinois State Museum. 



GENUS AVICULOPECTEN. McCoy. 



AVICULOPECTEN ORESTES. Wortlieil. 

 PI. XXII, Fig. 6. 



Aviculojirftcn (irt'xtea Worthen, March, 1884, Bulletin No. 2 of the Illinois State Museum 

 of Natural Hislory, page 18. 



Shell below the medium size, equilateral, broadly ovate when 

 divested of the ears; hinge line about equal to the greatest 

 breadth of the shell ; ears of moderate size and smooth or 

 showing only faint lines of growth; lateral sides diverging for 

 a short distance below the ears, and then broadly rounded into 

 the basal border. 



Surface ornamented with about 18 to 20 even, stout, rounded 

 ribs or costae, that are about twice as wide as the intervening 

 spaces. 



