1864. ] AND DENTITION OF THE LEMURID&. 625 
inflated, differing in this respect from Microcebus, as Dr. Peters has 
pointed out. The foramen for the entrance into the skull of the in- 
ternal carotid is very conspicuous on the basis cranii, being almost on 
the same transverse line as the foramen ovale, at the junction of the 
basi- and ali-sphenoids with the anterior end of the periotic. The 
posterior palatine foramina are small, and the bony palate (completely 
ossified) has the most anterior point of its posterior margin on a line 
with the middle or even with the anterior end of the last molar*. 
The optic foramen is, as might be anticipated, very large. One 
opening takes the place of both the sphenoidal fissure and the foramen 
rotundum. There is no malar foramen, nor any interparietal, and 
the preemaxillz do not join the nasals for so much as one quarter of 
the length of the latter. 
As regards the dentition, the upper incisors are always very small 
and subequal ; the first premolar always exceeds the second in verti- 
cal extent, but, like it, has only one large external cusp. 
The third upper premolar, however (like the corresponding tooth 
in Hapalemur), has two large and pretty equally developed external 
cusps, as have also the molars; so that the four posterior grinding- 
teeth have a similar form, when viewed externally, and are also pretty 
equal in size, what inequality there is in this respect arising from 
the inferior size of the last molar. Viewed from within (7. e. looking 
at the grinding-surfaces), these four teeth are also seen to be more or 
less equal+, the last premolar and the first two molars having very 
nearly the same dimensions; for each of these three teeth has two 
internal cusps, as well as two external ones, and the postero-external 
one is connected with the antero-internal one by an oblique ridge ; 
but the cingulum within is quite rudimentary or absent. 
The last upper molar is in some forms quadricuspidate, in others 
tricuspid, the postero-internal cusp disappearing. The oblique ridge, 
however, persists, and the tooth is generally intermediate in size be- 
tween the third premolar and the first two molars, which are the 
largest grinders in the upper jaw. The greatest difference between 
any two contiguous upper grinders is between the second and the 
third premolars, and not, as in Microcebus, between the third pre- 
molar and the first molar. 
In the lower jaw there is the same equality as in the upper, between 
the third premolar and the first molar; and the last four teeth are 
nearly equal in size, except that the last molar is in most species 
quinquecuspid. 
There appear to be constantly thirteen dorsal and six lumbar ver- 
tebre ; and, according to Dr. Peters}, the base of the gall-bladder is 
not (as in Microcebus and Lemur) turned towards the back. 
* In M. Gervais’s figure (p. 159) the palate is represented as rather elongated 
posteriorly : I have never seen such a condition in any Galago. 
+ The great similarity between the last upper premolar and the first molar 
above, in Galago sennaarensis, G. maholi, G. allenii, G. garnettii, G. crassicau~ 
datus, and G. pallida, was first pointed out by Professor Huxley: see ante, 
. 324. 
‘ + Reise nach Mossambique, p. 14. 
Proc. Zoou. Soc.—1864, No. XL. 
