876 
G. J. DE FEJ ÉRVÁR Y 
the faciès costales, its two sides advancing as if they were parallel to 
eachother, forming a small, narrowly rounded ball, to which corresponds a 
cup of short elliptic form, deeply hollowed in the ventral direction. 
These two latter features are obvious also on the sacral vertebrae of F. 
Cayluxi ( —V. Filholi). (Textfig. 8/). An interesting difference in d i m e n- 
sion is obtained by comparing the length of the dorsal vertebra of V. 
Cayluxi figured by De Stefano (measured from the middle of the border 
of the ball to the anterior edge of the cup), to the widest part of 
the centre of the vertebra (between the extremities of the facies costales) 
(Textfig. 8c); in this case, in the species mentioned, the length almost 
equals the breadth, the difference being about 2*6 mm. only, whilst in V. 
Hof manni this difference is so conspicuous that the length of the dorsal 
Fig. 4, t Varanus Hojmanni Rog. Two anterior dorsal vertebræ, a dor^ally, b ventrally 
viewed. — Nat. size — Stätzling, «Dinotheriensand*. — Authors pen drawing after photo¬ 
graphes in Roger, op. cit., Taf. Ill, Fig. 12 — 13. 
vertebra, taken from the extremities joining the facies costales, does not 
even reach the border of the cup, about 8*5 mm missing to attain the whole 
width. (Textfig. 4). The disparities therefore, as far as I was able to 
establish, are sufficiently striking and important to allow a specific separa¬ 
tion of these two Varanus forms, as the characters mentioned derive from 
the basic structure of the vertebrae and present therein 
essential dissimilitudes. The real merit and absolute certainty 
of these observations could naturally only be obtained by precise compa¬ 
rison and examination of original remains. 
A more arduous task is met with whilst attempting to establish diffe¬ 
rences between V. Hofmanni and V . marathonensis Weith., these two 
forms appearing to be identical as before mentioned in the prefatory 
historical part. However so important a systematic question not being 
solvable on consideration of mere appearance, I shall, despite this 
seeming identity,’ deal with F. Hofmanni as a separate species. Com¬ 
paring the vertebræ of F. Hofmanni and F. marathonensis , I have been 
able to state the following differences : the vertebræ of F. Hofmanni as 
