Progress in Mammalian Palaeontology. — Osborn. 213 
Primates, Carnivores and Perissodactyls can hardly be over- 
estimated. 
At the same time the zoogeographical relationships of 
our Lower Eocene (Soissonien) have been extended by the 
discovery of a French Creodont (Paheo7iictis) in America 
and of an American Creodont ( Pachyacna) in France. Still 
more surprising and important is the discovery 1 in the Mid- 
dle Eocene of Dasypoda {Metacheiromys), armadillos with 
canine teeth and with provision for a stout leathery if not 
osseous carapace. This absolutely establishes the Cretac- 
eous if not Basal Eocene zoogeographical relations of North 
and South America, and adds another fact to the growing 
evidence that North and South America were related in the 
Mid-Cretaceous and perhaps Early Tertiary and then sepa- 
rated again until the Pliocene. 
Our phylogenetic results have been mose encouraging 
in some directions and most baffling in others. Still more 
striking than ever before is the fact that the Lower and 
Middle Eocene fauna of Perissodactyla, Artiodactyla, Car- 
nivora. Cheiroptera, Monkeys, and true Rodents, an essen- 
tially modern fauna, is without any known direct affiliation 
with the Basal Eocene fauna (Meseutheria) (Compare Fig. 
2). Mingled with this essentially modern fauna are the 
numerous survivors of the archaic fauna, namely, the Cre- 
odonta, Condylarthra, Amblypoda, with which should cer- 
tainly be reckoned the Edentata (Paratheria, Thomas) and 
probably the Insectivora. 
The phylogenetic successions of the families within, 
these archaic orders have been much more clearly traced, 
namely, the pedigree and adaptive radiation of the Creo- 
donts into specializations of various kinds'. Among the 
Amblypoda the law of long-skulled and short-skulled phyla 
has again been found to prevail, in proof that the genera 
about which there was such a heated discussion, namely, 
Tinoceros as a relatively short-skulled form and Loxolojyho- 
don as a relatively long-skulled form, really represent two 
valid and distinct phyla. 
1 Omi.h'.n. H. F. An Armadillo from the Middle Emote {Bridger'i of 
North America. Mull. Amer. Mus. Nat. Hist., vol. xx. L904, pp, 163-165. 
■3 Matthew, \V. I). Additional Observation* on the Creodonta Bull. 
Amer. Mus Nat. Hist., vol. xiv, 1901, i>i>. i-::s. 
