I.ÖNNBERG, ON A NEW ORYCTEROPUS FROM NORTHERN CONGO. 25 



the liindmost milkmolar lias a different shape and has two 

 roots. But the same author found another of the members 

 of the milkdentition, the third from behind much larger than 

 the others and as that had almost the same shape (fig. 9 

 d) as this one, they might perhaps be homologous. The 

 other supernumerary teetli are much smaller, the next largest 

 (fig. 9 c) having a compressed crown measuring 2 mm. in 

 length by 1 in thickness. The others (conf. fig. 9 a and b) 

 are still smaller with a maximum diameter of 1 mm. or less. 

 The smallest one sits a little behind the prsemaxillo-maxillary 

 suture and measures only about Vö nini. in diameter. Some 

 of the supernumerary teeth have evidently cut the gum as 

 they are worn off at the tip (fig. 9 c and d). Those that 

 are not worn have more or less conical tips (fig. 9 a), but 

 are as a rule compressed. The 

 crown is small compared with the 

 root and has a smaller diameter y^ 



than that of the adjoining part (^ \ ! 



of the root. The roots of these V V 



small teeth are complete and , 



closed, — their growth is thus t^.. n t., , ^ • . ,^„. 



' , ^ Fig. 9. The 4 pöste rior super- 



limited, — the roots are of t en numerary teeth of the same 



drawn out in narrow ends. The specimen as is shown in fig. 8 



d the hmdmost one. Twieo en- 



shape of these small rudimentary larged. 



teeth proves that the ancestors of 



the Orycteropus of the present day have had teeth with lim- 

 ited growth and mos t likely compressed conical (or perhaps 

 bicuspid^) praemolars. The distinction between a crown and 

 a root can be quite plainly seen in these teeth, and they 

 differ through this markedly from the columnar func- 

 tional teeth which are similar from one end to the other. 

 That is, when they are worn they have this appearance, but 

 before they have cut the gum they are provided with a short 

 conical crown not covered by cement. The latter substance 

 which otherwise surrounds the columnar tooth ends at the 

 base of this short conical crown and forms there a kind 

 of coUar, which is somewhat swollen at its upper börder 



^ For the former bicuspidity speaks the fact thatthe small remaining 

 ci-own does not sit sjanmetrically on the root, but towards on side. It 

 may therefoi^e represent the remairis of the larger of two cusps, the smaller 

 of which has already disappeared completely. 



