17H 
SOME NEW AND LITTLE KNOWN CREODONTS. 
scpanite and that an alisplienoid canal is present. The American species present 
some imi>ortant deviations from this arrangement. The condylar foramen is situated 
ncfirer the medium line than in M. Filhol’s specimen and in H. cruentus there is an 
e.Kcc‘(‘dingly minute foramen immediately in advance of it, which does not seem to 
occur in //. horridus. The foramen lacerum posterius is placed as in the cynoid 
series close behind the tympanic bulla, instead of being isolated as in H. bracliyrhyn- 
chiis, and the carotid canal seems to be found with it, though this I cannot definitely 
state. Tlie foramen lacerium medium is situated as in the dogs and the same may be 
said of the stylo-mastoid foramen. The foramen ovale is placed opposite the glenoid 
cavity and owing to the breadth of the basisphenoid at this point is widely separated 
from its fellow of the opposite side. I have examined many skulls of the four 
American species, but none of them show any alisphenoid canal, a very important 
deviation from tlie species described by M. Filhol. In some American specimens a 
shallow pit occurs where the posterior opening of the canal would be, and this may 
possibly represent the remnant of such a canal. An unusually wide interval occurs 
Ix'tween the foramen ovale and the foramen rotundum, which is close to the sphenoidal 
fissure anti this to the optic foramen. These three foramina are enclosed in a com- 
mon groove formed by the ridge already mentioned which runs downwards and back- 
wards along the frontal, orbito- and ali-sphenoids. The posterior palatine foramina 
are placetl opjwsite the interval between pm. 4 and m. 1 ; the anterior are narrow 
ovals and reach close to the incisive alveolus. The infra-orbital foramen is placed far 
forward immediately over pm. 3 ; the lachrymal foramen is single and opens within 
the orbit. As Professor Cope has shown, three venous foramina connected with the 
lateral sinus are present in Hyofiiodon, the postglenoid, postparietal and mastoid. 
The lirain. Gervais^ has figured and described a cranial cast which he attributes 
to 11. leptorhynckus. “ J’ai pu observer une partie d’un moule cerebral naturel de 
1 Iliprnodon lepforhynchris et y constater la presence de circonvolutions bien plus 
semblables a celles des carnivores des deux groupes des Felis et des Hyenes qu’ a 
relies du Thylacyne. C’est le moule de la moitie posterieure d’un hemisphere cerebral 
de ce (amivore extrait de la partie correspondante de la boite cranienne sur une piece 
recuedlie dans la lamagne d’Auvergne par I’abbe Croizet. 
‘ On y volt la moiti6 iwsterieure de la circonvolution de la faux ou quatrieme 
circonvohition de la face convexe qui s’ aargit en avant pour recevoir le sillon crucial, 
mais sans que ce sillon ait ete conserv^ et la troisieme circonvolution ou circonvolu- 
tion internu-diaire inteme bien nettement separee de laprecedente ainsi que de ce qui 
reste arricrc de la seconde circonvolution ou circonvolution intermediare extenie. 
, . . ^ ^ ondre, comme chez les Felis et les Hyenes, avec la branche montante 
im.^-rieure de la circonvolution sylvienne dont la branche anterieure n’est pas visible. 
t. VI, p. 127, pi. VI, fig. 5. 
Gervais, Nouv. Arch. d. Mus. 1^= Sr. 
