352 G. J. DE FEJÉR VÁR Y 
Let ns now go over to an examination of «Palaeovaranus Filholi» 
described by De Stefano. It is with regret that I must point to the fact 
that in spite of his erudition, De Stefano dopa not dispose of the required 
expertness in zootomy, nor of sufficient knowledge regarding the variation 
of different os teologica! characters, whereby necessary zoological 
practice failing, correct judgment in the matter cannot be afforded. 
Thus the distinction from F. Cayluxi is decidedly forced. The right to a 
specific difference is already a priori rendered problematic by the fact of 
the fossils having been found in the same place and s t r a t a 
as V. Cayluxi; therefore the phenomenon is in itself improbable of two 
species of Varanus living; in the very same spot and age — in Europe espe¬ 
cially, — as in the Palaearctis of the old Tertiary period this genus could 
in np case have possessed the richness of species as for instance the genus 
Lace.rta in the Quarterly period and of nowadays — which would explain 
the existence of several species in like ages and places. The «differences)) 
mentioned by De Stefano are the following: 1° The maxillary teeth (p. 
409) «sono conici, appuntati, compressi lateralmente, un poco arcuati 
alla punta, leggermente striati alla base e sottili tanto al margine anteriore 
quanto a quello posteriore.» Besides this, as the author writes, they also 
differ from V. Cayluxi Filh. inasmuch as they are «più gracili, meno appun¬ 
tati, meno arcuati, meno compressi lateralmente e striati leggermente alla 
base.» It is a known fact that the teeth of Reptiles vary considerably even 
in the same individual; as factor to this, the age of the individual as well 
as the position of the teeth in the maxilla or mandibula also play their 
part. Moreover Reptiles teeth are apt to fall out or. break off, whereafter 
the regenerated tooth does not for some time correspond in size with the 
others. De Stefano seems to have given no attention to these facts. I take 
it for granted that every herpetologist will share in my opinion as to the 
appreciation of this feature. This f i r s t c h a r a c te r d o e s not there¬ 
fore in any way prove the specific difference, and for 
my part I see nothing else in these particularities than the expression of indi¬ 
vidual variation, which seems all the more plausible by the insignificant 
difference in gradation conveyed by De Stefano s words : «più, meno, legger¬ 
mente.» 1 2° The second difference between Varanus Cayluxi and «F. Filholi » 
would be that the cava glenoidea of the vertebrae of the former is ellipsoid, 
whilst the same with «F. Filholi » «benché sia di forma leggermente elittica, 
pure è quasi tanto lunga che larga.» It is obvious by this description that 
De Stefano has not examined the variations of the caudal vertebrae of 
1 The absolute conformity of the teeth is strikingly apparent on De StefaïtoV 
PL IX, Fig. 8 & on PL X, Figs. 15 & 18. 
