hovns no more constitutes affinity to the ruminants than it does in the 

 case of the "horned-toad." 



They are simply an analogous development on a proboscidian basis. 

 The few affinities which this group exhibits outside the Proboscidia, are 

 to the Perissodactyla, as I was the first to show, and among these, to 

 Palaotlierium and RMnocerus. As to the name " Dinocerata," I have 

 been induced to use it in the sense of a suborder, but am now satisfied 

 that even this vise is uncalled for, and shall employ the family name 

 Eobasileidce instead. On equally good bases the camel and Tragulus 

 should be erected into new orders. 



Another critic less courageous than Prof. Marsh, since he hides under 

 the aegis of the "Eds." has attacked (Am. Jour. Sci. Arts, 1872, 489) my 

 statement of determination of the Cretaceous age of the Bitter Creek 

 coal, citing five authorities as having previously made the same determi- 

 nation. I have shown (Proc. Acad. Nat. Sci., Phila., Jan. 14, 1873) that 

 but one of these references relates to the region in question, and that the 

 critic was ignorant of the geography or literature of the subject, or both. 

 He, however, repeats (loc. cit., 1873, 231) that Mr. Meek "referred Dr. 

 Hayden's collection from Bitter Creek at Point of Rocks to the Creta- 

 ceous." a fact I had previously pointed out, and adds that I am in error 

 in asserting that Mr. Meek attached interrogation marks to all his Coal- 

 ville determinations (200 miles west), as he cites two Gardia and two 

 Inocerami as from Coalville and without the question. More careful ex^ 

 amination would have shown my critic that the two Oardia and one Ino- 

 eeramus are stated to be from localities remote from both Coalville and 

 Bitter Creek. 



But there is no indication in my original note of a design to ignore the 

 useful labors of the gentlemen who have written on this subject ; nothing 

 was farther from my intentions, in so issuing an early notice of my own 

 observations, than to ignore the opinions of Mr. Meek, with which I have 

 become pretty well acquainted through pleasant association on the same 

 geological survey. Had they been coincident with my own, I should 

 have mentioned them, although unpublished. Mr. Meek will, however, 

 soon speak for himself. It requires but a casual examination to show 

 that the criticism is captious and uncalled for, and that its author is only 

 play in j aid to the champion above considered. 



II. 



I now turn to another subject, the raising of which is due also to Prof. 

 Marsh. He has very commendably made himself acquainted with the 

 literature of the .authors who had previously written on these extinct 

 Probosaidia, though not in time to prevent his redescribing some of the 

 genera and species. But unfortunately he does not tell us all that he 

 knows. He knows perfectly well that my descriptions antedate his by a 

 month and more, and that he is posterior to Dr. Leidy, by two months 

 at least. He is however not strong enough to state the nomenclature 



