FOSSIL VARANIDAE AND MEGALANIDAB. 
418 
ics carried to an unusual extent — on the entai side, indeed, the cusp is flat 
and, above the middle of the base, even impressed in the centre ; on this 
side there are but four feeble ribs, bifurcating as usual as they approach 
the base, on which is a cingulum surmounting the line of attachment to 
the jaw ; on the outer side the cusp is moderately convex and conspicuously 
ribbed. The ribs resulting from the confluence of pairs, which in this case 
cover the basal two-fifths of the crown, in their upward course follow the 
sinuous contour of the tooth, and are traceable nearly to the apex. The serra¬ 
tion of the acute caudal edge is distinct and regular, and passing over the apex 
extends upon nearly a third of the rostral margin. The whole tooth has 
a graceful sigmoid curve caudad. Its height and breadth at the base are 
thrice those of the corresponding tooth of V. varius — wherefore, on the 
assumption of like proportions throughout, it represents a Varan of about 
sixteen feet in length. 1 
An imperfect distal end of a young femur wanting the epiphysis 
may be provisionally referred to this species.» (See also observations in 
the critical chapter, «Varanidæ of Australia»). 
Hah.: Kings Greek (Darling-Downs). 
B) Mr. de Vis’ second paper (1900) furnishes but a very cursory 
survey of the matter, containing no anatomical or phylogenetical appre¬ 
ciation of this highly interesting form, his unique observation concerning 
the latter being that: «In the conformation of the 
jaw and proportionate size of the teeth F. dirus 
appears to be more closely represented in life by 
the Papuan species, V. salvadorii than by any of the 
Australian monitors . . .» «In length and breadth 
this maxillary is about twice greater than that of an 
example of V. salvadorii, which measures, in the 
skeleton, 7 feet in length.» Xo figures are given for 
comparison with the recent V. Salvadorii mentioned, 
nor is any reference made to other Australian Moni¬ 
tors, which, perhaps, should also be considered 
with regard to an at least approximate statement 
of phylogenetic relation existing between V. dirus 
and other Monitors, recent or fossil. 
Having no skeleton of V. Salvadorii Ptrs. & Doria at my disposal, 
I am reduced to the necessity of making mere combinations 
concerning the systematic value and phylogenetic relationship of this 
fossil species. V. dirus is also one of the little-known, or better said, 
1 I do not believe that this Varan would have surpassed in length V. siva- 
lensis (11 feet) or would have reached Megalania (14 feet) ! 
Fig. 15. t Varanus dints 
De Vis hom. ine. — Nat. 
size. — King’s Creek (Dar¬ 
ling-Downs). — From De 
Vis, On Megalania &c., 
PI. IV. 
