6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 149 



Artiodactyla under the Ungulata. The basis of this classification was 

 presented in greater detail in his "Classification of the Ungulate 

 Mammalia," published the same year (1882e). It is also this year 

 (1882d) that Cope reported receiving foot material of Periptychus 

 which led him to remove the periptychids from the Phenacodontidae 

 as a third family of the Condylarthra. 



Cope's ideas on condylarth classification were essentially crystal- 

 lized by the time of his "Tertiary Vertebrata" (1884b) with little 

 change since 1882, except that he had withdrawn the Proboscidea 

 from the Taxeopoda, but included the Hyracoidea, suggesting a 

 closer relationship of the latter to the Condylarthra. His treatment 

 of Meniscotherium in this volume covers in detail the osteology of 

 the skeleton, so far as it was then known, and is the most thorough to 

 date. The more generalized part of this description appeared in a 

 review of the Condylarthra in the American Naturalist for 1884(a) 

 and as a separate brochure. 



Later statements by Cope concerning Meniscotherium were essen- 

 tially in defense of his interpretation of its relationships. In 1886 he 

 criticized Schlosser (1886) for including Meniscotherium in the 

 Perissodactyla instead of the Condylarthra, in placing more emphasis 

 on teeth than on feet. In the following year he disputed Pavlow's 

 (1887) assumption that Meniscotherium belongs to the Propalaeo- 

 theriidae and is perhaps a synonym of Propalacotherium, reiterating 

 his belief in the importance of foot structure in interpretations of 

 relationship among ungulates. 



Cope's briefly held interpretation (1881a) that Meniscotherium 

 belonged with the chalicotheres was evidently favored by Schlosser 

 (1886), as he regarded Meniscotherium as a perissodactyl with 

 primitive feet and with teeth strikingly like Chalicotherium. This 

 relationship is unquestioned in 1902, as evident from the statement, 

 "Die Chalicotheriiden endlich stammen zwar aus Nordamerika — 

 Meniscotherium — . . ." Although Zittel in 1893 followed more 

 closely Cope's arrangement with the Meniscotheriidae, Phenacodon- 

 tidae, etc., in the suborder Condylarthra, but under the Ungulata 

 rather than Cope's Taxeopoda, Schlosser in a revision of Zittel's 

 texts in 1911 and 1923 still regarded Meniscotherium as the ancestor 

 or near the ancestry of the chalicotheres. 



No doubt Schlosser was early confirmed in his conclusions regard- 

 ing chalicothere affinity by Osborn (1891), who felt that the teeth 

 of Meniscotherium pointed strongly toward a relationship with the 

 chalicotheres, but awaited information on the structure of the feet. 



