0. C. Marsh—Additional Observations on Dinocerata. 293 
Pennsylvania, and a second cast is in possession of Dr. W. C. 
Reiter, of Pittsburgh, Pa. 
Before closing, I may remark that the sandstone, on which 
é 4 
these tracks are found, like that, on which Dr. King 
as of animals passing over the surface, but to what class refera- 
ble I cannot tell. It is, moreover, covered with the most 
They were given by me to Prof, Leo Lesquereux, and by him 
pwarded to Prof. Agassiz. I have not learned the result of 
errors in Prof. Cope’s recent publications on the same subject. 
Some of these mistakes were made b Prof. Cope in describing 
his own specimens; some by misunderstanding the c ters of 
- enty in number, Prof. C not answered. He 
however, endeavored to break the force of my criticism by a gen- 
eral denial, which evades the main issue between us, as I have 
recently shown in the American Naturalist for March (p. 146). 
He says, in substance, that one species 0 leus is nt 
* Geologi rt of Pennsylvania, vol. ii, p. 868. _ 
pe Deena vee Arkansas, p. 314. 
Am. Jour, Sct.—Tutrp Serims, Von. V, No. 28.—APRIL, 1873. 
19 
