1901.] LEMUE MONGOZ AND L. RUBBIVETSTTEE, 263 



(3) the characteristic position of its postero-medial wall, as seen 



from behind, when the skull is held in a horizontal position, 



with the basis directed upwards (PI, XXII. fig. 10), 



There are other species of Lemurs (eg,, Lemur macaco, Lemur 



nigerrimus. Lemur coronatus) in which the pars verticalis of the 



palatal advances into the cavum nasale in a slightly oblique direction ; 



but in none does it form a high vertical wall as in J^emu,r mongoz, 



which therefore is by this character alone at once to be distinguished 



from all the other species. 



Lemitr fulvus, generally confused «'ith Lemur mongoz, is pre- 

 cisely the one which exhibits no trace of a similar wing-like 

 structure, there being no pneumatic cavity intercalated between 

 the posterior region of the orbit and of the cavum nasale respec- 

 tively. An equally striking character of the skull of Lemur fulvus 

 is the great vertical extension of the sphenoidal sinus (PL XXII. 

 fig. 9, ss), which produces a considerable and sudden change of 

 level between this part of the basis and the cavum nasale in 

 advance of the sinus sphenoidalis, the former coming to be situated 

 much higher \ 



2, Lemde rubriventee. 



Lemur ruhriventer, I. Geofir. S.-H., C E xxxi. p. 876 (1850) ; id. 

 Cat.meth.p. 71(1851); H.Schlegel, Nederl.Tijdschr,Dierk,iii.p. 75 

 (1866) ; id, Mus. Hist. Nat, Pays-Bas, vii. p, 311 (1876) ; Jentiuk, 

 Mus, Hist, Nat, Pays-Bas, ix, pp. 61, 62 (1887) (exc. cran. nos. o, 

 jy, s) ; A, Milne-Edwards et A. Grrandidier, Hist. Nat. des Mammi- 



feres (Hist de Madagascar, ed. A. Grandidier), x. tome v. 



Atlas ii. plates 168-170 (1890) ; Jentink, op cit. xi. pp. 72, 73 

 (1892) (exc. sp. d) : Forsyth Major, Proc. Zool. Soc, Lond, 1899, 

 p. 554. 



Lemur jlaviventer, I. Geoffr. S.-H,, 0. E. xxxi, p, 876 (1850) ; 

 id. Cat. meth. p, 71 (1851) ; A. Milne-Edwards et A. Grandidier, 

 op, cit. pi. 191 (cranium). 



Prosimia rujipes, J. E. Gray, Ann. Mag. Nat. Hist. (4) vii. 

 p. 339 (1871); id. Proc. Zool, Soc, Lond, 1872, p, 852, pi. 69 

 (nee Milne-Edwards, P. Z. S. 1893, p. 177). 



At the Society's meeting of May 2, 1899 -, I gave expression 

 to some doubt against the correctness of the view brought forward 

 by Milne-Edwards ^ that Gray's Prosimia ruflpes is the female 

 of Sclater's T^emur nigerrimus. My observations may be epitomized 

 as follows : — 



(1) Gray's species was based upon a male and a female speci- 



men, both of them rufous. 



(2) I myself have collected numerous specimens of both sexes 



1 This is seen also in Grandiclier's plate 189. figs. 3, 6 (" Lemur mongoz ") & 

 pi. 193. figs. 3, 6 (" Lemur albimanus "). Von Lorenz had already rightly guessed 

 that the latter plate does not represent the skull of Lemur alhimamis 

 ( = L. mongoz, L.). 



a Proc. Zool. Soc, Lond. 1899, pp. 553, 554. 



■'' Proc. Zool. Soc. Lond. 1893, pp. 177, 178. 



18* 



