FOSSIL VARANIDAE AND MEGALANIDAE. 
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of the yet dubious Saniva, the whole suborder Platynota — as far as may 
be judged to-day — is known in Europe only, inasmuch as the two 
families Aigialosauriclae and Dolichosauridae of the other gens, the Dolicho- 
sauromor'pha , were also exclusively found in Europe, in the Cretaceous 
formations of England and Dalmatia. It is only the more distantly related 
suborder Mosasauria which spread over a larger sphere, so that its diffe¬ 
rent forms may be met with in the Nearctic region also. As regards the 
territory from which the whole suborder Platynota originated — to which, 
agreeing with Osborn and Fürbringer I do not reckon the Mosasauria - 
and whether these ancient forms, inscribed by Nopcsa (op. cit. p. 61) 
under the name of « Platynota adhoc incognita», may be considered as having 
sprung from the Palæarctic Regions, or whether their origin may already 
be traced in the Nearctic part of the Kænogea, remains to be decided by 
further investigation. We have up to now absolutely no data in hand to 
solve these problems, all the less as these ancient forms themselves are yet 
unknown to us. 
Therefore putting aside every unfounded speculative Combination 
and judging strictly from the facts known to-day, it may be taken for gran¬ 
ted that the family Varanidae originated from Europe — and only 
eventually from America, and that its first fossil representatives 
were obtained from the South-West, on the territory occupied in the pre¬ 
sent times by France, — or may be from the Eocene strata of America . 
It has already been mentioned that in the Pa læo gene the climate of 
North-Africa and of South-West Europe was tolerably similar ; despite this 
fact however no sufficient reason would be afforded for presuming that 
the primordial origin of the Varanidae should be searched for in Africa, 
since the palæogeographical c o n d i t i o n s — as has been already 
seen in reference with V. Cayluxi — do not even in principal 
admit of such a supposition. It seems probable that Varanidae went over 
to Africa at a later period, either by means of the communication existing 
with Asia in the N e o g e n e (Textfig. 6), or p e r haps from Europe, 
through the Gibraltar-Passage. 
It is interesting to note, in connexion with Africa, that in Madagascar 
Varanus is not forthcoming. Which fact considering the probable rapidity of 
the extension on this territory, permits the surmise of this genus having 
only much later, in the Pliocene, spread over West Africa, at the time when 
Madagascar was already an independent island. We have as yet met with 
no remains proving the eventual previous existence of the genus Varanus 
in Madagascar, from where it would have since disappeared, and it would 
be difficult to give a biological explanation of such a phenomenon. 
The geological succession of the fossil remains of Fa- 
