
H. F. OSBORN — MAMMALIAN PALÆONTOLOGY 97 
The zoogeographical relations of this fauna, already established by some 
parallels with the Cernaysien of France, have been perhaps extended by 
discovery of the Notostylops beds in Patagonia (AmeGuiNo"'). Faunal unity 
with the extremity of South America if confirmed will be of great signifi- 
cance ; it appears to be probable but perhaps not absolutely demonstrated. 
PROVISIONAL PHYLOGENY OF RHINOCEROTOIDE A, AMERICA AND EURAS A : 
I RHINOCEROTI/DAE AMYNODONT HYRACODONT. 
ei — 
D. simus R. indicus 
D. sumafrensis D.bicomis | R.sondaicus 
D.simorrensis 
D. sansaniensi 
D. douvillei 
D.advenum 
D.mmutum |A filhoi 
CAENOPUS 
TRIGONIAS | 
Genus Genus Genus 
ACERATHERIUM TELEOCERAS AMYNODON 
Kaup *  Aalther > Mars, 
| Europe and | Europe and | Asia, Europe | Europe and| Afria, | E 
| | 
Fire: 3 
The Polyphyletic Law Illustrated in the Rhinoceroses. 
The Rhinocerotoïdea early divided into the Hyracodontidæ (ïi), known only in America, 
Ammynodontidæ (ii), known in America and Europe, and the Rhinocerotidæ (i). The last family of 
true rhinoceroses prove to include at least seven distinct phyla corresponding to seven genera 
which extend back as far as the Middle Miocene if not into the Oligocène. 
The most important single phylogenetic result is the strong evidence 
which has been brought forward for the ancestral relationship of the Tæ- 
niodonta (Ganodonta) of the Torrejon to the Gravigrade Edentata (Worr- 
MAN ?), borne out by careful comparison of many parts of the skeletons of 
Psittacotherium and allied forms with those of the gravigrade sloths. In- 
1 Quadro Sinoptico de las formaciones terciarias y cretaces de la Argentina. An. 
Mus. Nac. d. Buenos-Aires, t. viii, Julio, 1902. 
? The Ganodonta and their Relationship to the Edentata. Bull. Amer. Mus. Nat. 
Hist., Vol. ix, 1897, pp. 59-110. 
VIe ConGr. INT. Z001., 1904. 
où 
