12 EINAR LÖNNBERG, MAMMALS COLLECTED IN CENTRAL AFR1CA. 



In the semiadult male n:o 165 the conditions (Pl. IV, fig. 1) have altered consider- 



ably. The triangulär portion of the nasals is almost as before, but at either basal corner 

 the nasals have pushed somewhat forward on top of the premaxillaries so that they 

 more completely surround the upper end of the nasal opening. Their breadth thcre is 

 nearly the same as in n:o 40 viz. 26,3, but about 24 mm. behind the free basal margin 

 the nasals appear to end in a sharp point. The shaf t-like process has thus dwindled away 

 and is broken off. In the place where the rhomboidal expansion ought to have been 

 and above the same to the eyebrow-ridge is a confusion of sutures. It is thus apparent 

 that the posterior parts of the nasals have been encroached upon, partly by the inter- 

 orbital parts of the maxillaries, and partly by the frontals so that they have been so to 

 say partly broken up in small pieces, partly entirely suppressed. 



The skull of the adult f emale has unf ortunately been so badly damaged by the shot 

 that almost the whole facial region has been torn away, but the interorbital region is 

 left. There the part of the nasals which has been termed the shaft is well defined with 

 sutures from the surrounding parts of the maxillaries which extend into the orbits, and 

 this portion of the nasals form a prominent sharp ridge. At the narrowest place of this 

 ridge the nasals measure only 4 mm. The portion which corresponds to the rhomboidal 

 expansion in the young animals can still be discerned, and even above the same remains 

 of the nasals can be followed to the eyebrow-ridge, although the sutures on the sides 

 are irregular. 



In the old male (Pl. II, fig. 1) there are no sutures to be seen in the nasal region. 

 The extension of the nasals may thus only be conjectured. The anterior triangulär por- 

 tion is thickened and broadened and, although all sutures have disappeared, the com- 

 bined anterior width may be estimated to about 40 mm. The triangulär portion is con- 

 tinued backwards and upwards into a distinct nasal ridge, but this is broader (about 9,5 

 mm.) and more rounded off than in the f emale. In the place where the rhomboidal ex- 

 pansion of the nasals is found in the young, the nasal ridge merges into an irregular thick- 

 ening of the bone which continues up to the eyebrow-ridge. 



In the young Gorilla n:o 166 there is a small piece of bone 21 mm. longand 13 mm. 

 broad intercalated between the supraoccipital and both parietals. In the young n:o 

 168 there is a similar piece of bone about 13 x 12 mm., but in this case a t the anterior end 

 of the parietal suture between the parietals and the already unified frontal. These are 

 no doubt individual anomalies. 



The dentition of the young male n:o 166 (Pl. IV, fig. 4) is as follows: 



di 1 , di 2 , de, dp 1 , dp 2 , m 1 

 di u di 2 , de, dp x , dp 2 , m, 



but inside the incisors and canines there are holes in the bone through which the perman- 

 ent teeth are to come up. mr and m 2 are also partly formed and to be scen in their 

 cavities in the bone. It is of interest to note the great length of the root of de of the lower 

 jaw, as it measures about 25 mm. in length and is open at the end. 



The dentition of the young female n:o 168 is quite simila,r, but there is in the lower 

 jaw also a hole in the bone inside of tlp t . 



