PF/rALODUS. 



PeTALODUS ALr.EGHANIENSlS. 



Leidy: Jour. Ac. Nat. Sc. ISoG, 101, riato XVI, Figs. 4 to G; Pr. Ac. Nat. Sc. 



1859, 3. 

 tVcariun cxtinvtus. Leidy: Pr. Ac. Nat. Sc. 1855, 411. 

 Petalodus destructor. Newberry and Wortbeii : tied. Stir, llliuois, vol. ii, I'al- 



iBontology 35, Plate II, Figs. 1 to .'!. St. John : Haydeu's Eei). Geol. Sur. 



Nebraska, 1872, 241, Plate III, Fig. 5. 



Described page 312, and represented by Fig. 3, Plate, XVII. From the 

 Carboniferous formation of Kansas, Nebraska, Iowa, Illinois, and In- 

 diana. 



Ichthyodorulites. 



XYSTRACANTHUS. 



Xystracanhus arcuatus. 



Leidy : Pr. Ac. Nat. Sc. 1859, S.- 

 Page 312, and represented by Fig. 25, Plate XVII. From the Carbonif- 

 erous formation of Kansas. 



'asteracanthus. 



Asteracanthus siderius. 



Leidy : Pr. Ac. Nat. Sc. 1870, 13. 



Described page 313, and represented by Fig. 59, Plate XXXII. From 

 the sub-Carboniferous formation of Tennessee. 



Rai.^:. 



ONCOBATIS. 



Oncobatis pentagonus. 



Leidy : Pr. Ac. Nat. Sc. 1870, 70. 

 Page 264, and represented by Figs. 18, 19, Plate XVII. From the Plio- 

 cene of Sinker Creek, Idaho. 



TRYGON. 



Trygon . 



Indicated Ijy the Ijasal portion of a caudal spine, represented in Figs. 54, 



55, Plate XXXII. It resembles the corresponding ])ortion of the caudal 



spines of our common whip-sting ray, Pastinaca hastata, and would appear 



to have pertained to a species of about the same size. Tlie anterior, shining, 



45 G 



