1864.] AND DENTITION OF THE LEMURID&. 617 
According to Dr. Peters, there are 13 dorsal, 7 lumbar, and 3 
sacral vertebrze*. 
To this well-marked form Dr. Peters, as has been said, has applied 
the generic name Microcebus, and justly so if it belongs to the same 
genus as does the Microcebus rufus of M. Isid. G. St.-Hilaire (the 
Lemur pusillus of Geoffroy and Rat de Madagascar of Buffon), which 
is the type of that genus. 
The skull and tarsus of Geoffroy’s Lemur pusillus have been figured 
by M. de Blainvile under the name Lemur murinus+, and the external 
form and dentition by M. Gervais. 
Dr. Peters notices as distinctive characters of the Lemur pusillus 
of Geoffroy, as compared with his (Dr. Peters’s) Microcebus myoxinus, 
**much shorter ears, not half the length of the head; longer fingers 
and toes; a longer and more pointed snout, also noticeable in the 
skull; the greater production forwards of the premazille ; the ver 
much smaller size of the openings in the palatet, and the shorter 
symphysis of the mandible.” 
I may add that, judging from M. de Blainville’s and M. Gervais’s 
figures, the premazille and nasals in M. pusillus are so much pro- 
duced above and below the anterior nares, that the outline of the 
lateral border of this opening is (when the skull is viewed laterally) 
very deeply concave. 
The upper incisors are also much more distant from the anterior 
margin of the premazille, though as much anterior to the canines as 
in M. myoxinus. Also the first premolar is less vertically extended 
than the second ; but this is perhaps owing to the individual not being 
quite mature. 
The two pairs of upper incisors are represented in M. Gervais’s 
figure as equal ; they are nearly so in M. de Blainville’s figure, and 
they are described by him as “ sub-égales et trés-petites”’ §; but as 
those of his Lemur milii are also spoken of in the same phrase 
(although in the plate representing the skull of that species the an- 
terior incisor is represented as decidedly larger than the posterior), 1 
am inclined to believe that the anterior pair are really larger than 
the posterior in Lemur pusillus as well as in Microcebus myoxrinus, 
the more so as it is almost impossible that so careful and accurate a 
naturalist as Dr. Peters should have omitted to notice such a striking 
difference between his M. myoxinus and the L. pusillus of Geoffroy 
as would have been the equality of the upper incisor teeth of the 
latter. 
The formation of the ¢arsus also may, I think, for the same reason, 
be safely assumed to be similar in these two species. 
The LZ. pusillus of Geoffroy has very often been associated with 
the Galagos on account of the structure of its foot—amongst others, 
* Reise nach Mossambique, p. 17. 
t T assume that the Lemur murinus of De Blainville is the Lemur pusillus of 
Geoffroy. Both Dr. Peters and Dr. Wagner are satisfied on this point. 
¢ The posterior palatine foramina, however, are still very large: see Gervais’s 
‘Mammiferes,’ p. 173. 
§ Ostéographie, Lemur, p. 39, pl. 11. 
