EDWARD D. COPE. 



73 



Paleontology has cleared up the phylogeny of most 

 of these orders, but some of them remain as yet unex- 

 plained. This is the ease with the Cetacea, the Sirenia 

 and the Taxeopoda. The last named order and the Mar- 

 supialia can be supposed with much probability to have 

 come off from the Monotremata, but there is as yet no 

 paleontological evidence to sustain the hypothesis. No 

 progress has been made in unraveling the phylogeny of 

 the Cetacea and Sirenia. The facts and hypotheses as to 

 the phylogeny of the Mammalia may be represented in 

 the following diagram : 



Diplarthra Hyracoidea Insectivora Rodentia Chiroptera 

 Proboscidia \ Anthropoidea / Edentata Carnivora 



Amblypoda 



Quadrumana 



Condylarthra 



Multituberculata 



Marsupialia 



I 

 Monotremata 



It will be readily seen from the above diagram that 

 the discovery of the Condylarthra was an important 

 event in the history of our knowledge of this subject. 

 This suborder of the Lower Eocene epoch stands to the 

 placental Mammalia in the same relation as the Thero- 

 morphous order does to the reptilian orders. It general- 

 izes the characteristics of them all, and is apparently the 

 parent stock of all, excepting x^erhaps the Cetacea. The 

 discovery of the extinct Bunotherian suborders united 

 together inseparably the clawed orders, excepting the 

 bats ; while the extinct order Amblypoda is the ancestor 



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