Cope.] llv) [Jan. 16, 1874. 



ture was so low as to render it incapable of igniting tlie free hydrogen 

 issuing with it. After a lew moments' heating, the tube was hermetically 

 sealed. A liquid phosphorus was produced differing markedly from that 

 obtained by boiling with caustic potash. It was very mobile, of a clear 

 amber color, and on solidifying, assumed the tough, waxy state. 



The physical peculiarities exhibited by the modification which we have 

 studied seem fairly to entitle it to a place as one of the allotropic condi- 

 tions of phosphorus. Indeed, they are much more strongly marked than 

 those upon which the elastic variety of sulphur are based. 



ABSTRACT OF THE REMARKS OF PROF. COPE AT THE 



MEETING OF THE AMERICAN PHILOSOPHICAL 



SOCIETY, JANUARY 16, 1874. 



An analysis of the osteotology of the extinct ruminant Poebrotlierium 

 (Leidy), from the Miocene of the Western territories, determines some 

 interesting relations to the living and extinct members of the order. The 

 cervical vertebrae indicate aflfinity to the Gamelidce, and there is nothing 

 in the remainder of the structure to contradict such relation. The separa- 

 tion of the OS trapezoides is found in the camels, and very few others only 

 among Ruminantia, but in the presence of the trapezium, Po'ebrotheriuin 

 shows relationships to more ancient types, as Anoplotheriidce', &c. The 

 reduction of the digits to two, and the separation of the metacarpals, 

 point in the same direction ; indeed, the number of carpals and meta- 

 carpals is precisely as in Xiphodon. But the mutual relations of these 

 bones are quite different from what exists in that genus, and is rather 

 that of the Gamelidoi and other Ruminants, or what Kowalevsky has 

 called tlie " adaptive type." This author has seen in the genus Gelocus, 

 Aym., from the lowest Miocene or upper Eocene the ancestor of a number 

 of the types of the order, but among these he does not include the Game- 

 lidce. The present genus is a more generalized type than Gelocus, in its 

 separate trapezoid and distinct metacarpals, and represents an early stage 

 in the developmental history of that genus. It also presents affinity to 

 an earlier type than the TraguUdce, which sometimes have the divided 

 metacarpals, but the trapezoides and magnum co-ossified. In fact, Po'e- 

 brotherium as direct ancestor of the camels, indicates that the existing 

 Ruminantia were derived from three lines, represented by the genera 

 Gelocus for the typical forms, Poebrotlierium for the camels, and Ilyae- 

 moscJius for the Tragulidm. The first of these genera cannot have been 

 derived from the second, on account of the cameloid cervical vertebrae of 

 the latter, and all three must be traced to the source whence wei'e derived 

 also the AnoploiheriidcB, perhaps the little known DicJiodontidce, 



The two distinct metacarpals, separate trapezium and trapezoides, 

 cameloid cervical vertebrae, and dentition characterize this type as a 

 peculiar family, which may be called Poebr other iidcn. The genus from 

 which it takes its name was originally referred by Leidy to the Gamelidoi. 

 The genera Hypertragulus, Cope ; Leptomeryx, Leidy ; and Hypisodus 

 Cope, are probably TraguUdcB. 



