1895.] Parallelism in the Genus Palaeosyops. 623 
Quite a large number of species of Titanotherium have been 
already described, but as a whole this genus is remarkably 
homogeneous in the characters of the species, and it is very 
uncertain how many there really are. The deeply concave or 
saddle-shaped skull is typical, I believe, of all the known spe- 
cies. The case with Palaeosyops is quite different, as this genus 
exhibits a great variety in its specific forms, fully as great, 
if not greater than Palaeotherium of the Middle Eocene of 
Europe. : 
Within the past summer some exceedingly valuable material 
of Palaeosyops has been collected for the American Museum 
of Natural History by Mr. O. A. Peterson of the Museum; and 
this has just been described in bulletin form by Professor 
Osborn. We are greatly indebted to this bulletin for its im- 
portant information in regard to the stratigraphical relations 
of the skulls of Palaeosyops. This: material was collected in 
the country just south of the Uinta Mountains, and the deposit 
which oceurs in this area was always supposed to pertain only to 
the Uintaor Upper Eocene. Mr. Peterson discovered skulls of 
a species of Palaeosyops in this region, namely, P. megarhinus, 
which is typical of the Bridger proper, and, in fact, he found 
one skull of this species or a variety of the same, which is the 
earliest one known of thisform. Thisskull came from the base 
of the beds under the Uinta, which is considered to be the bot- 
tom of the Bridger. Mr. Peterson informs me that Palaeosyops 
occurs from this position in the beds as far up as just beneath 
the Uinta proper. Furthermore, in the uppermost of the 
transition beds, between the Bridger and Uinta proper, Mr. 
Peterson discovered a number of large skulls of a supposed 
new type of Palaeosyops, but I think I can quite safely say 
that this form really belongs to the genus Telmatotherium 
Marsh (Leurocephalus S. & O.). The characters of these skulls 
nearly demonstrate my views as to the phylogenetic relation- 
ship of Palaeosyops to Telmatotherium, and in my memoir 
on the former genus I remarked “I consider that Telmatothe- 
rium is the most highly specialized genus of the Palaeosyopi- 
nae approaching more closely in its dental characters (skull 
unknown at that time) to Diplacodon than any other genus of 
