832 General Notes. 
This important memoir is divided into two portions as indicated in 
the above title. I refer to the second part first in order, by record- 
ing the discoveries it announces. Prof. Rütimeyer has made the 
highly interesting discovery of a species of Phenacodus at Eger- 
kingen, which he names P. europæus. He also refers species from 
the same locality to the genera Protogonia, (?) Mioclænus, and ©) 
Pelycodus, and to the new genus Meniscodon. Unfortunately al 
of these species are known from the teeth only, so that the refer- 
ences are not yet final. He also gives descriptions of new specimens 
of Cenopithecus lemuroides Riitim. and Proviverra typica Ritim. 
In the first part of the memoir, Prof. Riitimeyer discusses the 
relations of the various members of the Ungulata, with reference 
to their classification. This consists chiefly of a criticism of the 
system proposed by Cope, and the results he reaches are expressed 
as follows: (p. 62). 
First.—That the categories of Ungulata, based by Cope on 
the nature of the mutual carpal and tarsal articulations, do not 
furnish exact definitions for systematic use. Although they furnish 
instructive series of modifications of the mechanism of motion, they 
do not offer sharp lines of distinction. Especially can the so-called 
condylarthrie have a very relative value, and between it and the 
diplarthrie is there no sharp line. i 
Second.—The plan of structure which characterizes the superior 
molars of the Condylarthra consists in a disposition of the tubercles, 
to which he applies the name trigonodontie, since there are three 
principal tubercles arranged en triangle, two external and one inter- 
nal,so that the cross-valley of the crown is closed within. Tt is this 
type of dentition which is common among lemurs and Insectivora, 
and which prevails among Carnivora. It is thus probable that 
trigonodontie is to be regarded as an earlier and more primitive 
form of molar than those of the zygodont (quadritubercular) piar 
The selenodont type appears to have arisen from trigonodon 
ancestors, r t 
Third.—The trigonodont structure of superior molars as 18 pre’ 
in the Condylarthra is by no means confined to American Ungulat, 
ut is found in Europe even to generic details; so that 1t 18 ede = 
that the foot-structure of the Condylarthra will be also found 0 
he ge . ica alone for 
Fourth.—It is therefore not necessary to look to America aton 
the first known ancestors of the horse. heen 
Fifth.— Except the Dinocerata, which, like the Toxodontis, i ped 
limited range in America, the types of Mammalia have deve z r 
in such complete parallelism that we are Pae ed to look 
common and extensive raphical source for them. ‘ 
Siath—A mong the $ wa a the Cænopithecus of Egerkingen 
