36 UN THE C'KANTAL CHAKACTERS OF LAC'EliTA JACKSO.VI. 



iS^or can I find any differences in the istyle of scaling of tlie 

 upper dorsals between Dr. Torniei^'s diagnosis and that given 

 for the type of the species by Mr. Boulenger, which scales, according 

 to the latter, and further verified by myself, are stated to be 

 " rhomboidal, keeled, juxtaposed, or subimbricate," eveiy one of 

 these conditions occurring in the Elgon specimens as well as in 

 Lacerta vauereselli. 



The number of scales aci-oss the body, viz. 38 in the latter, also 

 is in accord with the mean of the Elgon series of specimens ; and, 

 as regards the femoral pores, this has been finally disposed of, 

 both by what has been made known [antea, p. 34), as well as by 

 a remark made by Mr. Boulengei' in connection witli this point 

 in his description of the Ruwenzori female. 



As already pointed out in the diagnosis of the skull of Laceria 

 jacksoni, there are no teeth on the pterygoids any more than 

 in L. vauereselli. No difference appears to exist in I'egard to 

 the supratemporals as described for this species by Dr. Tornier 

 fi'om their condition in the Elgon specimens, in all of which a small 

 tympanic scute is plainly visible. 



Neither is a distinct gular fold recognizable in all specimens, at 

 least in the stricter sense, as it is often apparently absent in im- 

 mature individuals, such as seems to be the case with Dr. Tornitr's 

 type, judging b}' the dimensions given by him — an assumption 

 which is further corroborated by the fact that its sex has not been 

 mentioned. 



The length of the posterior extremity also varies gieatly 

 individually — in some Elgon examples it scarcely attains the 

 axillaiy^ pit, whilst in others it reaches well beyond the collar- 

 edge. 



The geographical range of this species, so far as the increased, 

 but at piesent still scanty, material on I'ecoid permits one of 

 judging (17 specimens, including Dr. Tornier s L. vauereselli), 

 appears to be a strictly equatorial one. 



Its habitat, moreover, seems to be generally restricted to the 

 mountainous region of that part of the Central African plateau, 

 or immediately west of it, which culminates in its highest peaks, 

 an area generally acquiring considerable altitude. 



Its ultraplatycephalous shape, concurrently with its sombie- 

 coloured garb, at once seems to denote a form occupying high 

 ground, differing from those of the plains, with generally more 

 massive skulls and more vividly contrasting colour- patterns, 

 in the same manner as, for instance, Lacerta mosorensis differs 

 from Lacerta muralis var. cav}2^esiris or serpa, and L^acerta muralis 

 var. monticolO' from the var. hocagii. 



