No. 379.] REVIEWS OF RECENT LITERATURE. 525 
the solitary and chain forms of Cyclosalpa are given in detail, and 
an account of the subneural gland in this genus is appended. The 
paper is an abstract of a dissertation accepted at Johns Hopkins. 
University for the degree of doctor of philosophy. CHP 
Relationships of American and European Mammalian Faunas. 
— Mr. A. Smith Woodward concludes a most valuable résumé of the 
history of the mammalian fauna of Europe and America (Natural 
Science, May, 1898) with the following considerations as to the place 
of origin of the various elements in the two worlds. At the base of 
the Eocene it is evident that the faunas of the east and the west were 
essentially identical. As they are traced upwards they gradually diverge. 
The first noteworthy difference is the great development of the 
Condylarthra in America, and the rise in the Eocene of the large 
specialized Amblypoda, of which only a single genus (Coryph don) 
has been found in the corresponding fauna of Europe. On the other 
hand, the still larger hoofed animals of the sub-order Proboscidea 
seem to have originated in the Old World, and did not reach America 
until the late Pliocene. 
The Perissodactyla—the tapirs, rhinoceroses, and horses— appear 
to have advanced on a parallel course on the two continents, though 
in America both the rhinoceroses and the horses became extinct at 
the close of the Pliocene, the former without acquiring the character- 
istic horn, 
Among Artiodactyla, both the deer and pigs seem to have been 
approximately parallel in their development in both continents, only 
differing in some minor branches, which soon became extinct. The 
camels, however, are clearly American throughout, only wandering 
into the Old World by Asia in the Pliocene. It is almost equally 
probable that the oxen originated in the Old World. 
Among Carnivora, the Creodonta are both American and European; 
but on the former continent they only pass upwards into the dogs 
(Canide), weasels (Mustelidæ), and the aberrant cats of the family 
Nimravide, while in Europe they are succeeded, not merely by these 
families, but also by the Viverride, Hyænidæ, Felidae, and Ursidæ. 
The viverroids and hyænas never reached America, but the true.cats 
and bears arrived on that continent at the close of the Pliocene. 
Of the Primates, the primitive lemuroids appeared in the Eocene 
similarly on both continents; but in North America they soon became 
extinct, while in the Old World they were followed by the true apes, 
and still have some specialized survivors. 
