FOSSIL VARANIDAE AND MEGALA NIDAE. 
347 
Varanus Lemoinei No pcs a 
Var anus sp. Nopcsa 
Varanus deserticola By. 
Passing over to a critical review of these genera’s and spe¬ 
cies’ 1 systematic value, let us first examine the rights entitling the subsis¬ 
tence of the genus Palaeovaranus Bilh. In the light of oui- present know¬ 
ledge from a zoological point of view, — and not considering as. 
any benefit to the peculiar furthering of science the endeavours of most 
palaeontologists, to establish new species and genera, 2 — a negative 
answer ought to be given. I have not found a single morphological charac¬ 
ter which might distinguish the genus Palaeovaranus from Varanus and 
such differences as palaeontologists may have surmised between the two 
genera, can only be attributed to precarious knowledge in zoology. 3 The 
2 The first mentioned real Varanus alluded to by Jourdan as «un reptile 
très voisin du monitor terrestre d’E g y pt e» is no more referred tó¬ 
in any publications having lately appeared. 
2 It is a fact that frequently in consequence of either the fragmentary state of the 
remains or inaccessibility of the already described original ones, thus confined to fre¬ 
quently insufficient data, synonyms necessarily arise. This undoubtedly is at 
length less , harmful for the system than would be the practice, resulting from careless 
determination, of crowding in some alieady known systematic unit any new fossil in too 
imperfect a state to allow accurate definition. We must however also remark that many 
are the «new» species and genera which arise without these compelling cir¬ 
cumstances enforcing a provisional establishment of species and genera* 
The fault consists generally in a «necessity of establishing new species» which we may 
meet with just as frequently among palaeontologists not having mastered the required 
zoological knowledge, as among zoologists studying palaeontological material for the 
purpose of comparison with recent one, yet not having acquired sufficient experience 
and erudition on the subject in general, or as regards literature and system specially 
referring to palaeontology. — Concerning palæozoological nomenclature see: Fejérváry, 
Notts de Nomencl. Palæozool., appearing in: Bull. Soc. Vaud. Sc. Nat., Lausanne 1919. 
3 In his account of the Phosphorites of Quercy De Stefano (op. cit. p. 406 — 407) 
describes two fragments of the occipital region of a Lacertilian ; comparing these with 
recent material, he states having not been able to discover any likeness between them 
and the corresponding parts in Monitors, I g nanas or Ophisa urs . According 
to De Stefano the shape of the latter fossil bones bore greatest resemblance to the 
occiput of the Australian genus Trachysaurus, to which he allies the Quercy form under 
the generic name of Pro rachysaurus. So far as a comparison could be established between 
Trachysaurus and « Protrachysaurus » on the base of De Stefano’s somewhat defective 
photographs representing the latter form, I must confess that in some respects the likeness 
seems a striking one, hereby differing a good deal from the cranium osseum of recent 
Monitors. However the question might arise whether these fragments of skull could 
not be regarded as belonging to the reptile we examine here under the name of Varanus: 
Caylux ? In t h is case the genus Palaeovaranus would be a fully justified one. I wish 
