(ilS Systematic Paleontology — UrrEK Devonian' 



width as the ribs tlicinselves. The shell normally assumes the circular 

 form and curved ribs represented hy Hall's figures, but this outline is 

 seldom retained in the shales, though always sliown in the liarite replace- 

 ments occurring in the lime nodules of the New York strata. 



In Xew York the species is very abundant in the Styliola limestone 

 (Genesee) and in the olive Naples shales throughout the region between 

 the Genesee Eiver and Cayuga Lake and is occasionally seen in the lower 

 eastward horizons. West of the Genesee Eiver, in the Chautauqua sub- 

 province, it is seldom seen. 



Paracardium doris is quite generally diffused throughout the Genesee 

 member and the beds containing the Naples fauna in the Woodmont 

 member. 



Length 7 mm. ; height 5 mm. 



OccMn-e?ice.— Jennings Formation, Genesee Member. On the hill 

 directly southeast of Cumberland ; west of Corriganville on the Barrel- 

 ville Eoad; just west of Wolfe Mill; and on the Parker farm near Bur- 

 lington, West Virginia. Woodmont Member, Naples Fauna. National 

 Eoad east of Gilpintown. 



Collections. — Maijland Geological Survey, New York State Museum. 



Paracardium delicatulum Clarke 

 Plate LX, Figs. 17, 18 



Paracardium delicatulum Clarke, 1904, N. Y. State Mus., Mem. vi, p. 304, pi. 

 xi, fig. 4. 



Descripiion. — To this species, which has already Ijeen observed in the 

 Styliola limestone on Canandaigua Lake, New York, is referred a small 

 shell with hair-lined surface and sulK-ircular outline. A drawing of the 

 New York form is introduced here for purposes of comparison. The 

 surface of the shell bears from 50-70 very fine simple riblets, this char- 

 acter in itself serving as the distinguishing feature of the species. 



Length 5 mm. ; height 3 mm. 



Occurrence. — Jennings Formation, Genesee Member. On the Na- 

 tional Eoad just west of Wolfe Mill, near Cumberland. 



Collection. — Maryland Geological Survey. 



