No. 376.] THE CHRIACIDA AND THE PRIMATES. 261 
five genitals makes it possible to conclude that in this case the 
missing ambulacral row (using the nomenclature of Lang, Comp. Anat., 
vol. ii, p. 321, Macmillan, 1896) is the right posterior one. 
BIOLOGICAL LABORATORY OF HAMLINE UNIVERSITY, 
St. PAUL, MINN., February 1, 1898. 
RELATIONSHIP OF THE CHRIACIDA TO THE PRIMATES. 
CHARLES EARLE. 
Ir would be interesting if some especially clear-headed paleontolo- 
gist would define the order Creodonta and explain how it is to be 
separated from the Insectivora. If we include forms like Chriacus 
in the Creodonta, we shall be obliged to follow Wortman’s sugges- 
tion and unite the creodonts and insectivores in one common group. 
It must be granted that the creodonts of the Puerco were well 
differentiated and somewhat specialized; this is proven by the pres- 
ence of such forms as Deltatherium and Didymictis, the latter genus- 
having developed already the true sectorials of the higher carnivores, 
It remains to be shown whether the peculiar upper molars of the 
Mesonychide are primitive or degenerate. If Dissacus is really the 
ancestor of Mesonyx, then this series illustrates an important point 
in tooth morphology, and would help to settle the vexed question 
whether the order of appearance of the cusps of the true molars is 
really different from that of the premolars. In Dissacus and Pachy- 
zna, for example, one would be led to conclude that the antero- 
external cusp of the upper molars was the first one to appear and its 
position had not been changed. In the case of these teeth it is hard 
to believe that there had been any rotation inwards of the protocone 
such as the advocates of the triconodont-tritubercular theory would 
make us believe. 
The genus Chriacus and its allies have little in common with the 
above-mentioned creodonts, and I fail to see why they should be 
classified with them. It appears to me to be out of the question to 
imagine that the primates have any close relationship to the Condy- 
larthra such as Cope supposed. That the condylarths were all 
ungulate types has been admitted, and, in fact, it is one of their 
important diagnostic characters that they were hoofed quadrupeds. 
It has been most interestingly shown by Dr. W. D. Matthew how 
closely one of the earliest condylarths, Euprotogonia, approaches in 
