636 MR. ST. GEORGE MIVART ON THE CRANIA_ [Nov. 22, 
have yet had opportunity to observe, in all the Anthropoidea the pos- 
terior cornua of the os hyoides exceed in length the anterior cornua ; 
in all the Lemuroidea this proportion is reversed. Also that in all 
the Anthropoidea the internal carotid enters the cranium after tra- 
versing a canal passing through the bony periotic mass, which it 
enters at its posterior part; in all the Lemuroidea*, on the other 
hand, the internal carotid enters the cranium without traversing such 
a canal+, and mostly at the junction of the basi- and ali-sphenoids 
with the anterior end of the periotic. Finally, in all the Anthropoidea 
the foramen rotundum is normally distinct from the sphenoidal fis- 
suret; in all the Lemuroidea the two are very slightly separated, and 
in most species but one opening represents both these apertures. 
The suborder Lemuroidea appears to be naturally divisible into the 
three families Lemuride, Tarside, and Cheiromyidea—Galeopithecus, 
as I believe, forming no part of the order Primates. To the already 
well-known distinctions between these three groups I may add that 
in the Tarside the third digit of the hand is the longest, while the 
second and fourth digits are nearly equal—a combination which, I 
believe, occurs in no other species of thesuborder. Again in Tarsius 
alone, of all the Lemuroidea, is the orbit closed behind by a union of 
the malar with the alisphenoid§. This reappearance of a marked 
and exceptional character amongst Mammals (one otherwise quite 
peculiar to the Anthropoidea) is most interesting, as, if Tarsius is 
thus demonstrated to have a near connexion with the higher Primates, 
then, a fortiori, the higher Lemuroidea must have such also, and 
thus we have a strong argument against the complete separation, as 
a distinct order, of the last-named group, and a reason for their 
merely swbordinal distinction. 
In defining and grouping together the genera of Lemuride, it is 
particularly desirable to obtain precise and definite distinctions. As 
Dr. Peters justly observes||, mere external characters are of little 
* Having some doubts as to Cheiromys, Professor Owen very courteously fur- 
nished me at once with the information I required, and which his notes could 
alone supply. 
+ Unfortunately I have not had an opportunity of injecting and dissecting a 
specimen of the genus Lemur, and am therefore unable to speak of the course of 
the internal carotid in that form, except in the above negative way. 
+ There are two skulls of Gibbons in the Museum of the Royal College of 
Surgeons in which one opening appears to represent both the foramen rotundum 
and the sphenoidal fissure ; in other skulls of that genus, however, the two open- 
ings are very distinct. In Hapale the foramen rotundum is not readily seen 
when the skull is viewed anteriorly, being hidden by the ingrowth of the alisphe- 
noid ; and when visible, it is so small and distant from the sphenoidal fissure as 
to look like avery large Vidian foramen. 
§ In examining a skull in the British Museum I felt strongly persuaded that 
such a union existed, but doubted the accuracy of my observation on account of 
Professor Van der Hoeven’s direct assertion to the contrary, given in the Report 
of the British Association at Oxford, 1860, Tr. Sec. p. 134. But, as Burmeister re- 
presents this union most distinctly in several views of two distinct skulls (see ‘ Bei- 
trage zur n. Kenntiss d. G. Tarsius,’ tab. 7. figs. 1, 2,8, & 9), I think it possible that 
Prof. Van der Hoeyen may have formed his opinion on a skull presenting some 
individual variation, or perhaps even have overlooked the true line of union. 
|| Reise nach Mossambique, p. 18. 
