Douglass : New Merycoidodonts. 87 



In his definition of Merycochcerus he includes both M. proprius and 

 M. rusticus. The latter may belong to a different genus, as will be 

 seen later. 



One thing in Leidy's discussion of Merycochcerus is very interesting. 

 He says: "The mental foramen, like the infraorbital foramen is pro- 

 portionately larger than in Oreodon (Merycoidodon) . Perhaps this 

 difference in the size of the foramina, together with the other peculiar- 

 ities of the face, may indicate that Merycochcerus was provided with 

 large prehensile lips, or probably a short proboscis." (Page 203.) 



Just following the paper in which Leidy first described the type of 

 Merycochcerus rusticus is one by the same author entitled Remarks o?i 

 a Collection of Fossils from Dallas City, Oregon.* 



This collection consisted of remains of mammals obtained by Rev. 

 Thomas Condon from the Valley of Bridge Creek, a tributary of the 

 John Day's River. "The greater number and more striking speci- 

 mens belong apparently to a species of Oreodon, larger than any 

 previously described, and equaling in size Merycochcerus proprius. 

 Indeed so far as we are familiar with the skull of both, the two are so 

 nearly alike that one may be regarded as only a variety of the other, 

 or at most may be viewed as distinct species of the same genus. I 

 am, however, disposed to view one as the offspring by selection of 

 the other, and regard them as corresponding species of two genera, 

 which existed probably in different times or localities. 



"The species, which I propose to distinguish under the name 

 Oreodon superhus, is indicated by a mutilated skull, together with 

 mutilated crania and portions of jaws with and without teeth, of half 

 a dozen or more individuals." 



What we should undoubtedly consider as the type of this species is 

 the skull represented in Fig. 1, Plate I., of Leidy's Extinct Vertebrate 

 Fauna. 



In his Synopsis of the Species of Oreodo?itido3 b Cope included this 

 species in the genus Merycochcerus with other forms from Oregon and 

 Montana which did not belong there, and included Bettany's Mery- 

 cocha'rus temporalis in the species (/. c. , pp. 521-523). Cope says 

 (p. 522) : " Of this fine species I have nine crania extracted from the 

 matrix, and a good many not yet cleaned." If these are identical 

 with the type, the characters of this species ought now to be capable 



4 Proc. Acad. A T at. Sci. Phila., 1870, pp. III-113. 



5 Proc. Amer. Philos. Soc, 1S84. 



