XK CAMEL-LIKE PERISSODACTYLES ZOY. 
three-toed. It was intermediate between a Tapir and a Rhinoceros 
in size. It has been shown, too, from casts of the interior of the 
skull, that the cerebral hemispheres are much less convoluted than 
were those of Zitanotheriwm. 
Related to Palaeosyops is another primitive Titanothere, the 
genus Velmatotherium. This is also Eocene, from the Uinta 
Basin, the uppermost of Eocene strata. The skull of these 
creatures was rather elongated, and not unlike that of a Titano- 
there in general aspect. The dentition was complete and the 
canines not very large. The horns, which acquire so prodigious a 
development in the later Titanotheres, are just recognisable in at 
any rate many species of this genus 7elmatotherium, the name 
being thus by no means an apt one. Better was that proposed by 
Dr. Wortman, of Manteoceras or “prophet horned.’ The horns 
are small elevations upon the frontals just at the junction of 
these with the nasals, and, indeed, lying partly upon the latter 
bones. In 7. cornutwm the horns are chiefly borne upon the very 
long nasals, whose size contrasts with the same bones in the 
more highly-developed Zitanotherium. It appears to be quite 
possible that Titanothertwm was evolved from the genus 
Telmatotherium.' ¢ 
SuUB-OrDER 9. LITOPTERNA. 
Whether the Macraucheniidae should be considered as a 
separate group of Ungulata is a matter of dispute. Cope 
placed them in a special order of Ungulates which he called 
Litopterna. — Zittel, on the other hand, regards them as definitely 
Perissodactyles. One curious point of resemblance to existing 
Horses is shown—that is the presence of a pit in the incisor teeth. 
This matter seems to be so important as to need a placing of 
these forms in the neighbourhood of the Perissodactyles, even of 
the Equidae ; it is so peculiar a character, and apparently so little 
related to any obvious similarity in way of life, that it seems to 
mark a special affinity. Not so the fact that in Macrauchenia 
at any rate ‘the orbit was entirely surrounded by bone as in the 
Horse. We find that condition so frequently acquired in many 
groups,—a development from an earlier condition where the cavity 
for the lodgment of the eye is in continuity with the temporal 
1 See Osborn, Bull. Amer. Mus. Nat. Hist. vii. 1895, p. 82. 
