22 ARKIV FÖR ZOOLOGI. BAND 7. N:0 6. 



Potamoclioerus clioeropotamus johustoiii (Major). 



In the year 1897 (1. c. p. 367) Forsyth Major described a 

 new species which he named Potamoclioerus jolmstoni. The type of 

 this new species was a female skull from »Ngarawi River, Nkanga 

 in the North Nyasa District». The distinguishing characteristics 

 should be the »large size, the straight upper contour, and its slen- 



derness», molars and premolars large». I ha ve had the 



opportunity of examining and measnring this skull (91. 5. 9. 

 5) in Brit. Museum Nat. Hist. (conf. II table of measure- 

 ments), and stated the relative correctness of Majors' views. 

 Although this female skull is according to my terminology 

 only semiadult, it has the great upper mesial length of 372 

 mm. and is thus equal in length to the next largest male 

 skull of the true P. chosropotarmcs-tyipG. The parietal region 

 is broad, very much broader than in the P. choeropotamus 

 of the narrow-headed northern type but not quite as broad 

 as in those from Cape and Natal when they have attained 

 full size. In consequenee of the length of the skull the width 

 of the parietal flat area is only 11,0^0 of the upper mesial 

 length thus much more than in P. clioeropotamus maschona 

 from adjoining regions but not so much as in old specimens 

 from the south. The relative slenderness of the skull cannot 

 be taken into account as it is not fullgrown. The last molar 

 is large, but the same size may be attained by specimens of 

 P. choeropotamus. 



It was of interest to find that, since Major wrote his 

 paper, Brit. Museum had aquired a male specimen (B. M. 7. 

 2. 14. 1) which must be regarded as belonging to the same 

 race. It is an adult boar from Fort Manning, N. E. Rho- 

 desia, and its skull is larger than any other specimen of this 

 genus, having an upper mesial length of 422 mm. The width 

 of its parietal area is not less than 44 mm. and it is in this 

 respect superseded only by the old female described above 

 from Natal, but in consequenee of the length of the skull 

 this measurement is only 10,4 % of the upper mesial length. 

 In all other dimensions as well this skull shows larger abso- 

 lute measurements than other skulls of the P. cliosropotamus- 

 group. The great length of the skull causes, however, several 

 relative dimensions to be smaller in P. ch. jolinstoni. The 

 distance between the postorbital process and the lambdoid 



