346 
G. J. DE FEJÉR VARY 
regarded by him as posterior, assumes the appearance of an anterior one*, 
much resemblance may be traced between it and the second sacral, 
vertebra of a Crocodilian; the fact of the proc. trans v. projecting more 
from the u p p e r arches than from the centre of the vertebra is the 
only character withholding Portis from the supposition of the vertebra in 
question being truly that of Crocodilia. In his determination of these remains 
he ranges them with the Lizards, yet expressing a not too unfounded 
doubt as to their agreement with the «Famiglia dei Varani di ?». In spite of 
this uncertainty, expressed at the end of his paper as to the systematic 
position of the fossils : «possiamo già constatare che il Baurio volterrano 
non può entrare direttamente in alcuna delle famiglie , e tanto meno dei 
generi stabiliti per Baurii viventi», he nevertheless classes them, although 
adjoining a query, among the Varanidae, remarking (p.*28) that: «la famiglia 
a cui il Baurio volterrano apparteneva, doveva essere molto vicina a quella 
dei Varanidi . . .». Portis does not tell us why this fossil reptile should, 
have to be in close connexion with just the Varanidae in p a r- 
t i c ubar? According to him its ancestral character consists in the fact 
of the vertebrae being amphicoelous («il Baurio volterrano avendo probabil¬ 
mente tutte le sue restanti vertebre proceli, presentava la prima ver¬ 
tebra sacrale amficela») contrarily to the lizards of present days (p. 27) 
which, the «Ascalabote». group excepting, all have procœlous vertebrae. 
From the above we may, I think, safely conclude that Portis’ description 
and figures will hardly enable any herpetologist to form a correct idea as 
to the systematic position of this fossil, whose definition is made more 
difficult yet by its damaged state. However the drawings in natural size 
give us almost absolute certainty that no sort of connexion 
can be proved between the Progonosaurus pertinax Port, and the Vara - 
nidae presenting a totally different structure of the vertebrae and showing 
already in the lower Oligocene a différenciation corresponding to their pre¬ 
sent form. Nopcsa (op. cit.) likewise with some hesitation, also ranges the 
Progonosaurus with the Varanidae. I for my part think it best for the pre¬ 
sent to treat the former genus as «Incertæ O r d i n i s» and elimi¬ 
nate it altogether from the system of the Vara¬ 
nidae, I shall therefore no more refer to it in the course of this study- 
On base of what has been said above, the genera and specie* of 
European Varanidae would be limited to the following: 
Palaeovaranus Cayluxi File. 
Palaeovaranus Filholi Pe Stef. 
Varanus Hof manni Boger 
Varanus marathonensis Weith. (= Varanus atticus Nopcsa} 
