Geology and Paleontology. 833 
appears to be as nearly allied to the North American Mesodonta as 
to the European Adapis. 
I propose to offer some observations on these propositions, espe- 
cially to the first and second. The third, and those following, 
relating as they do to the important discoveries of Prof. Riitimeyer 
at Egerkingen, constitute valuable additions to the sciences of 
paleontology and mammalian phylogeny. 
e first proposition, that the characters of the carpus and tarsus on 
which I have relied for discrimination of the orders of Ungulata are 
insufficient for that purpose, is probably so far true, asa similar asser 
tion made with regard to all structural characters whatever would be. 
With the discovery of new forms, and the completion of phylo- 
genetic lines, the sharp demarcations we now employ as definitions 
will vanish. But I claim with regard to the case of the Condy- 
larthra, that such discoveries have not been yet made, and that Prof. 
Riitimeyer’s views on this point have been reached by reason 
of several misconceptions on his part. The supposition that the 
tarsus of Phenacodus (p. 14) resembles in any degree that of the 
rhinoceros and tapir, isan unaccountable error. Also (1. c.) the 
supposition that the carpus of those animals does not represent the 
diplarthrous type is an equally extraordinary misconception. So 
is (p. 15) the opinion that such small contact of the astragalus with 
the cuboid bone as exists in Phenacodus and Hyrax is diplarthrism 
comparable to that of Hyracotherium venticolum. 
ut supposing Prof. Riitimeyer’s view that the carpus of Phena- 
codus is proboscidian, and the tarsus rhinocerotic, to be correct, an 
priae distinct from Proboscidia and Perissodactyla would be indi- 
cated, 
The fact is that Prof. Riitimeyer, probably from want of speci- 
mens of Condylarthra, has not fully grasped the meaning of the 
taxeopod, and especially the Condylarthrous type of carpus and 
tarsus, That type is the unguiculate and carnivorous, accom- 
panying hoof-shaped ungues, and as yet no transitions to the usual 
ungulate type have been found within the Ungulata, except in the 
carpus of the Anthropomorpha (and the result is not typically 
ungulate). The Condylarthrous carpus and tarsus are also lemu- 
rime, and are well distinguished from other ungulate types. The 
structure of the astragalus of Dissacus among the Unguiculates 
Shows us what the transition will be like when it is found.' 
„The second proposition ascribes what Prof. Riitimeyer calls 
trigonodontie as a definitive and general character of the Condy- 
larthra. I must here record an objection to the introduction of the 
word trigonodont. It is proposed to replace the term tritubercular 
> the Ungulata, so that the latter phrase shall apply only to 
the Unguiculata. But there is absolutely no difference between 
' Transactions Amer. Philosophical Society, 1888, pp. 343-4. 
