620 MR. ST. GEORGE MIVART ON THE CRANIA_ [Nov. 22, 
myoxinus, M. minor, and M. pusillus in the existence of a consider- 
able diastema between the upper canine and the first premolar, and 
between the latter and the second premolar, and in the broader angle 
to the mandible. The third upper premolar also appears to approach 
in size the first true molar more nearly than in M. myoxinus, M. 
minor, and M. pusillus, and to be less vertically extended than in 
them ; but it is difficult even to judge from M. de Blainville’s plate, 
as one cannot tell what to attribute to abrasion of the teeth. In the 
considerable vertical extension of the first as compared to the second 
premolar, C. mzlii approaches M. typicus. Unfortunately I have 
at present no means of knowing the structure of the palate, the form . 
of the grinding-surfaces of the molars, or whether there is an inter- 
parietal bone—points I am also unable to ascertain as regards M. 
typicus and M.smithii. The principal reason, however, which would 
appear to me to justify the separation generically of OC. milit from 
M. myoxinus, M. minor, M. smithii, and M. pusillus*, is the alleged 
different and peculiar structure of the tarsus in the first named. 
That of M. pusillus, as figured (under the name Lemur murinus) by 
M. de Blainville+, shows an elongated calcaneum and naviculare, 
similar to that of the Galagos, though considerably less in degree, also 
an elongated cuboid ; but the astragalus is normal. In M. myozinus, 
as I have already stated, Dr. Peters’s measurements show a somewhat 
greater length of tarsus. That it is similarly constructed, however, 
is to be inferred from his silence as to any difference in this respect 
between his M. myoxinus and M. pusillus (De Blainville’s L. muri- 
nus), and the more so as he expressly asserts that in his M. myoxinus 
the calcaneum is one-third the length of the tibia, compares its tarsal 
structure with that of Galago and Lemur, and declares it intermediate 
between them. As far as I could ascertain in the specimen preserved 
in spirits in the British Museum (labelled C. smithii and so resem- 
bling M. myowinus), the os calcis barely attains one-third the length 
of the tibia. The proportions of the naviculare and cuboid could 
not be ascertained, but I have no doubt that they are the same as in 
M. myoxinus and M. pusillus. 
Now in C. mili, according to M. de Blainvillet, the tarsal bones 
are long ; but here “c’est l’astragale, et non le scaphoide seul, qui suit 
l’allongement assez prononcé du calcaneum, ce qui donne a chaque os 
du tarse de ce petit animal quelque chose d’assez particulier” ; and 
this is said immediately after describing the tarsus of M. pusillus 
(De Blainville’s L. swrinus) with which it is contrasted. Now, if on 
examination the difference here indicated should prove to be consi- 
derable, it would be an important character, and, I think, justify a 
generic distinction between Cheirogaleus and Microcebus. But the 
two genera would still have many points of affinity ; and, according 
* I do not add M. typicus, because I have, unfortunately, no means of ascer- 
taining the structure of the tarsus in that species, and because, judging from the 
skin, that part appears to be relatively shorter than in the above-mentioned 
forms, as I have before remarked. 
t Ostéographie, Lemur, pl. 10. 
¢ Ibid. p. 12. 
