Geological Society. 65 
present a sudden increase in size and change of form. The 
plane of the crown is triangular, with the base outwards, and the 
posterior and inner side convex: it supports three principal cusps, 
two on the outer, and one on the inner side; there are also two 
smaller elevations with a depression on the summit of each, situated 
in the middle of the crown, and the whole is surrounded with a ridge 
which is developed into a small cusp at the anterior and external 
angle of the tooth. The three true molars closely correspond with 
those of the Chzropotamus. ‘The sockets of the canines indicate 
that these teeth were relatively as large as in the peccari. 
The bones of the head are separately described: the palatal 
processes of the maxillary bones are shown to be rugous, as in the 
peccari; the eye to have been full and large, as indicated by the size 
of the optic foramen and the capacity of the orbit, equalling an inch 
in vertical diameter: the general form of the skull is described as 
partaking of a character intermediate between that of the hog and 
the hyrax, though the large size of the eye must have given to the 
physiognomy of the living animal a resemblance to that of the Ro- 
dentia. 
These indications, Mr. Qwen says, scanty though they be, of the 
form of a species nearly allied to the Cheropotamus, are extremely 
interesting, on account of the absence of similar information regard- 
ing that genus. The resemblance of the molar division of the 
dental system in the new genus, for which the name of Hyracothe- 
rium is proposed, and the Cheropotamus, is sufficiently close to 
warrant the conclusion, that the canines and incisors if not similar 
would differ only in form and proportion ; and that hence it may be 
ventured to solve analogically some of the doubts entertained by 
Cuvier respecting the dental characters of the Cheropotamus, and 
to affirm confidently that it had canines in the upper as well as the 
lower jaw. ‘The incisor teeth with the ossa intermaxillaria are 
wanting in the specimen of the Hyracotherium, and have not been 
found in any fragment of the Cheropotamus. 
2. The remains of birds described in the paper consist of a sternum, 
with other bones, and a sacrum, the former belonging to the collec- 
tion of the late John Hunter, in the Royal College of Surgeons, 
and the latter to the cabinet of Mr. Bowerbank. Both the speci- 
mens were obtained from Sheppey. The Hunterian fossil includes 
the sternum nearly entire, the proximal ends of the coracoid bones, 
a dorsal vertebra, the distal end of the left femur, the proximal end 
of the corresponding tibia, and a few fragments of ribs. Mr. Owen 
first shows, in approximating to which of the three great groups of 
birds, terrestrial, aérial, or aquatic, the Ornitholite belonged, that 
from the length of the sternum and the remains of the primary in- 
termuscular crest or keel, it could not have been a strictly terrestrial 
bird, though these characters do not prove that it was a bird of 
flight, as they occur in the Penguins or other Brachyptera, which 
have need of muscular forces to work their wings as paddles under 
water. In the present fossil, however, from the lateral extent 
and convexity of the sternal plate, the presence and course of 
Ann. & Mag. Nat. Hist. Sept. 1840. F 
