34 



EINAR LONNBERG, MAMMALS COLLECTED IN CENTRAL AFRICA. 



two small females, n:o 22 & n:o 24. These specimens may thus have been shot out of 

 the same band, but certainly in the same tract. 



Total length of skull 



Condylobasal length of skull 



Zygomatic width 



Breadth across m' 



Length of *jpper molar series 



Greatest transverse diameter of m^ ... 

 Palatal length from gnathion to hind margin 



of lateral incisure 



Capacity of the brain-cavity 



The dimensions of the brain-case of this species proves thus to be of about the same 

 size in some females as in the males, contrary to the usual condition among the Guenons. 

 Compared with the other considerably larger species this one seems to have a big brain. 

 The shape and size of the orbits and of the nasal apertuj^e is very variable as can be seen 

 on comparing figs. 2 a & b, and figs. 4 a & 6 of PI. VIII. 



The smaller males have also a shorter molar series than the larger females. The 

 shortness of the molar series of some specimens appears sometimes to depend more upon 

 the smallness of the premolars than that of the molars. Thus in the male n:o 25 the true 

 molars measure 15,2 mm. and those of the male n:o 23 15,6 mm. In other cases all the 

 teeth are diminished in size, f. i. the female n:o 24 (PI. VIII, fig. 5 6) has the series of 

 true molars only measuring 13,5 mm., while the same measurement of the female n:o 19 

 (PL VIII, fig. 5 a) is 17,7 mm. But the female n:o 24 ought probably to be regarded as 

 a dwarfed specimen. 



The degree of prognathousness is also rather variable in these skulls, and some of 

 them have a much more steep profile (cf. PL VIII, fig. 1 a &b and fig. 3 a & 6) than 

 some others. The anterior root of the zygoma is usually situated opposite the middle 

 of m^, but in the female n:o 17 it is placed further back above the posterior end of m^ 



It must also be stated that the variations in colour mentioned above do not stand 

 in correlation to the characteristics of the skull. It is true that the small-headed and small- 

 toothed female n:o 22 has the root of the tail rather light grey below, and that the male 

 n:o 25 are lighter at the same place than the male n:o 23, and that the former has smaller 

 head than the latter. But the female n:o 24 which has the smallest head and smallest 

 teeth, has the tail as dark below as any of the large-headed specimens. In a similar way 

 the big-toothed male n:o23 and ditto female n:o 19 have a slight reddish tint to the hairs 

 in the ear, but the same shade of colour is in the corresponding place better developed in 

 the small-toothed male n:o 18 (upper molar series 21,3 mm.), and in all other specimens 

 this shade is absent, if the skulls are small or large. 



Very old, teeth much worn. 



