GEOLOGICAL SURVEY OF THE TERRITOEIES. 437 



III readiug over the last proof of this list, it occurred to me that pos- 

 sibly the qnery alter the words " (^ret. l^o. f might be misunder- 

 stood as intended to express a doubt in regard to the Cretaceous age of 

 these species. Consequently, I struck out, with a pencil, the abbrevia- 

 tion '' Cret.," leaving it simply "jSTo. ?" after each of these species. 

 But afterward I thought there could certainly be no misonderstandiug 

 OQ this point, with the accompanying explanations, and made an effort 

 to rub oat the pencil-markings I had made in the proof. The printer, 

 however, being misled by the soiling of the paper, did not understand 

 what I wanted, and instead of leaving it " Cret. Xo. "? " in all these 

 cases, only left it so after one species ; while, after another, he struck 

 out " Cret.," leaving it merely " iS^o. ?"; after two others he struck out 

 the abbreviation " l^o/^. " leaving it " Cret., ? " and after two others he 

 struck it all out. 



In regard to the two Coalville species, by mistake of the printer, left 

 with only "Cret. ?" after them, I admit that it might aj^pear, to one 

 glancing hastily over the list without reading the remarks and explana- 

 tions on the preceding pages of the same report, that I had intended to 

 express doubts respecting their Cretaceous age. It certainly seems to 

 me, however, that any person reading, with even a moderate degree of 

 attention, my remarks and explanations respecting this list, and the 

 age of the Coalville and Bear River coal-bearing strata, in the same 

 rex)ort, ought to understand that I did not question the fact of these 

 beds belonging to the Cretaceous system. 



Again, in giving a list of the Cretaceous fossils collected by Dr. Hay- 

 den's party, at various localities during the summer of 1870,* in his re- 

 port of 1871, pages 375 and 376, I placed in it a few additional forms 

 from Coalville, nearly all of which are entirely distinct from any I had 

 before seen from there,,or, indeed, from any other locality. These are 

 mainly casts in hard arenaceous rock ; and as I had little or no time 

 then to work out and study them, I merely placed them in the Creta- 

 ceous list, without specific names, and with a mark of doubt in regard 

 to the genera to which fi.ve of them belong. I explained, however, in 

 the accompanying remarks, that I regarded them as Cretaceous species, 

 giving my reasons for so doing. 



I have been somewhat particular in giving the foregoing statement 

 of formerly published opinions respecting the age of the rocks under 

 consideration, because the question-marks used in the lists mentioned 

 have been alluded to as if they had been used to express doubts in regard 

 to the Cretaceous age of the coal-bearing rocks at Coalville and other 

 localities in this region ; and my opinion on this subject has been con- 

 sequently treated as if so vague and undecided that it was not even 

 necessary for any one, subsequently arriving at the same conclusion in 

 regard to the Cretaceous age of any of the coals of this region, even so 

 much as to allude to it.f 



Having thus briefly cleared away some misapprehensions in regard to 

 what has been well known for some years past respecting the Cretaceous 

 age of the coal-deposits of Coalville, Utah, and at Bear Eiver, Wyoming, 



*It should be reraembered that each of these lists only includes the collections 

 brought in from the explorations of the preceding summer, and that they vreve not in- 

 tended to include all of the known species that had previously been found in the same 

 beds, at the same localities. 



t See a paper on the existence of Binosauria in the transition beds of Wyoming, by 

 Prof. Edward D. Cope, read before the Am. Philosophical Society, 187;?; also, Remarks 

 on the Geolo^fy of Wyoming, by Prof. Edward D. Cope, Proceed. Acad. Nat. Sci. Philad., 

 December, lb72, page 279. 



