FOSSIL VARANIDAE AND MEGALANIDAE. 438 
migrated to Africa at a later period only, i. e. in the Pliocene 
or Pleistocene, by way of the continental connexion existing with Asia in 
the Neogene and at the beginning of the Diluvial age. (See Arldt, op. 
eit. Map 8, «Wanderungslinien im Pliocän u. Diluvium»). What has been 
said with regard to Africa is however only based on suppo¬ 
sition, no fossil remains having as yet been found to facilitate inves¬ 
tigations . 
Thus the Varanidae referred to by Gadow 1 as also by Fürbringer 
under the name of «Old-world Lizards» 1 2 migrated from West to East, 
across South Asia to Australia; the exact time of their extension 
Fig. 24. Present geographical distribution of Varanidae. — The Territories inhabited by 
Varanus being designated with blach. — From Gadow, rp. cit., Fig. 139. (Magnified). 
s o u t h-w est w a r d s, to A f r i c a, remains unknown for the present. 
The subtropical climate of Europe vanishing, the Varanidae subsisted 
yet some time in the Mediterranean regions (F. marathonensis Weith.), 
but cooler temperature accompanying the glacial period (Textfig. 23), and 
felt also in Southern parts, caused their definite removal from Europe. 
Regarding the Varanidae ’s eventual American distribution or origin, 
owing to the as yet most superficial knowledge of Saniva, the question 
remains to be cleared in all its points. 
1 Op. cit. p. 542. 
2 It seems that both authors follow LiDEKKERand Zittelìii considering Ljeidy’s 
American Saniva from Wyoming as an Anguinid; its relation with Varanidae has, 
since Leidy, only been lately again alluded to by Nopcsa. 
Annales Musei Nationalis Hungarici. XVI. 
28 
