34 PROCEEDINGS OF THE GEOLOGICAL society. [June 16, 
tamed that both the upper and the lower jaws above described belong 
to the same genus and the same species. For the penne I prapeee 
the name of Paloplotherium ; its dental formula is i eo 
s—s 3-3 
s pitegaineyo7 40; with the specific name annectens for the 
present known representative, as indicative of the transitional cha- 
racters which to a certain degree connect the Paleotherium with its 
eocene contemporary the Anoplotherium. The Paloplotherium has 
however several characters by which it differs from both ; amongst 
which may be mentioned, besides the absence of p 1 in both j jaws, 
the reduction of the third lobe in the last molar of the lower jaw to 
the tubercle ¢, in which simplification of m 3, the Ee re- 
sembles the Macrauchenia and Rhinoceros. 
The bones which contain the perfect series of the upper molar 
teeth form the middle and anterior thirds of the skull. Only the 
rhinencephalic compartment of the cranial cavity is preserved with 
the facial division: but the bones, though crushed and fractured, 
permit of many instructive comparisons being made with the Ano- 
plothere and Palzeothere, in regard to this part of their osteology. 
The orbits are relatively larger than in the Paleoth. crassum; and 
owing to the flattening of the frontals at the interorbital region, they 
have not so low a position as that which peculiarly characterises the 
Paleothere. In this respect, as well as in the minor convexity of 
the interfrontal region, the Paloplothere resembles the Anoplothere. 
The postorbital process of the frontal descends lower than in the 
Paleeothere, and in this character the skull resembles that of the 
Anoplothere. 
The curvature of the moderately strong malar bone forming the 
lower boundary of the orbit is convex downwards ; it is relatively less 
deep anteriorly than in the Anoplothere. The orbit is on the same 
vertical parallel as the last two molar teeth. The ridges continued 
backwards from the postorbital processes, curving and converging 
upon the frontal bone, are strongly marked by the sudden sinking of 
the temporal fossa which they define, but they do not rise above the 
level of the frontals: they converge at a less acute angle than in the 
Paleotherium crassum. 
The lachrymal bone is perforated by two foramina, defended ex- 
ternally by a small projecting tubercle. The rhinencephalic depres- 
sions* of the cranial cavity are vertically oblong, divided from the 
prosencephalic chamber by descending superior ridges, and from each 
other by a sharp vertical ridge (er ista galli) formed by the hinder 
margin of the coalesced prefrontals (lamina media ethmoider). 'The 
posterior parts of the ossified olfactory capsules close the anterior 
outlets of the rhinencephalic depressions, and were perforated, as 
usual, by the numerous filaments of the olfactory nerves, forming 
* T restrict the term ‘ olfactory’ to the chambers of the face containing the 
turbinal and other parts of the olfactory capsules. 
