EINAR LÖNNBERG, THE GENUS POTAMOCHGERUS. 33 



Major »the great slenderness of the snout.»^ I have had too 

 little material to ascertain the value of this. The width of 

 the nasal area of an old female P. 1. Jiova is about 39 to 40 

 mm. while in an old female of the broad-headed P. chceropo- 

 tamiis from Natal the same dimension varies from 43 to 49. 

 The difference is thus not verv great. If for instance the 

 typical skull of a boar of P. 1. hova figiired by Major (1. c. 

 p. 365) is compared with a male skull of P. ch. nyasoe the 

 former is certainly not more slender than the latter. 



The assertion by Major that in the »Malagasy species» 

 the nasal region is not »flattened nor angular laterally, but 

 rounded off», I do not understand. His own figures of a 

 Malagasy boar skull speak against it, but it is perhaps meant 

 to be valid only for the foremost part of the nasals, or for 

 the female skulls alone. In such a case it is not, however, 

 a distinguishing character as other female skulls of the genus 

 are similar in this respect, and the foremost portion of the 

 nasals in boars as well joins often the premaxillaries with an 

 even rounding. 



The apophyses above the canines are large and broad. 

 In consequence of their breadth the vertical through their 

 hind margin passes through, or near the middle of j)^ but 

 they are less sloping than for instance in P. ch. nyastx,. In 

 adult boars they seem to reach the level of the nasal surface. 



According to Major »the lower premolars [of P. larvatus 

 hova] have an even greater tendency to disappear than in 

 the Continental forms, so that in old animals we sometimes 

 meet with only one premolar.» This appears, however, to 

 be very different in different specimens. In a female specimen 

 of P. larvatus hova which was so old that in the upper jaw 

 m^ of both sides had been worn out and dropped, and on 

 the right side even m^ while on the left m^ was on the 

 verge of falling out, on the right side p'\ p^, and 2?^ remain 

 in use, and on the left p-, and p'"^. In the lower jaw the 

 condition of the molars is quite the same, on one side ms, 

 and 7712 remain, on the other only ms, but on both sides two 

 premolars are found in comparatively good condition. 



A comparison of the cranial dimensions (conf. table of 

 measurements II) shows that in most cases P. larvatus hova 



^ Gray speaks of »the narrowness of the nose with a ronnded upper 

 edge» (Ann. & Mag. Nat. Hist. ser. 4 Vol XV p. 46). 



Arl-ir för zoologi. Band 7. X:o G. 3 



