362 
G. J. DE FEJÉR VARY 
m a t i c a 1 value. Eerefence will yet be made to other details concer¬ 
ning this subject in the part treating of system. 
Finally, as regards Mr. Zietz’s «Varanus warburtonensis » I feel sure 
in presuming these fossils to be identical with Meg al anici prisca, 
its somewhat smaller size being the only mor¬ 
phological difference, referred to by the author’ 
as occurring between it and Megalania. Since in an earlier- 
stage of its development this reptile must most certainly have been 
smaller than in later ones, I see no reason whatever for separating 
at present the Warburton-River vertebræ from those of the Condamine 
River described by Sir R. Owen under the name of Megalania prisca 
and belonging thus, according to my opinion, to the separate family 
Megalanidae. 
Therefore only three fossil Yaranian species can be accepted as 
occurring in Australian deposits, all of them claiming due reexamination, 
description and representation, in order to exactly prove their systemati¬ 
cal ’position and value. 
* 
What has been said above has exhausted the list of fossil remains- 
of Varanidae known until now, which, as far as positive data demon¬ 
strate, all belong to the one gen us Varanus which fact can easily 
be attributed to the comparatively slight différenciation of these Platynota . 
It is true that earlier literature contains other genera ranged in the Vara- 
nidae family, most of these however proved incorrectly determined, inas¬ 
much as their systematic position classified them in entirely different 
suborders. Zittel for instance besides Varanus (op. cit. p. 608—609) 
mentions the following genera : Hydrosaurus Wagl., Palaeovarmms Filh., 
Thinosaurus Marsh, ? Tinosaums Marsh, ? Notiosaurus Owen! The fossil 
Hydrosaurus proved to belong to the family Dolichosauridae (under the 
name of Pontosaurus ), as has been stated in the historical summary 
of the European Varanidae ; at this same occasion the identity of 
Palaeovaranus with Varanus has also been demonstrated; the most su¬ 
perficially known American Thinosaurus (= Tinosaurus) has re¬ 
cently been defined as belonging to. the family Helodermatidae 1 ; whilst 
considering as a fact de Vis’ surmise of the Australian Notiosaurus 
being synonym of Megalania? It must be here remarked that the genus 
1 See Nopcsa, op. cit., p. 49; Broili, op. cit. p. 210. 
2 De Vis, On Megalania andfits Allies, Proc. Boy. Soc. of Queensl., Vol. VI, Bris¬ 
bane, 1889, p. 97. 
