REPTILIA : VARANOSAURUS 85 



described in Varanosaurus, has a like form in both the Poliosauridae 

 and Clepsydropidae. 



Femur (Plate XXXVII, Fig. 3). — The femur resembles that of 

 Theropleura more closely than that of Dimetrodon in its relatively 

 greater terminal expansions and especially in the greater extent 

 of the digital fossa, which reaches nearly a third of the length of 

 the bone. Four femora of the collection are very nearly of the 

 size and shape of the one figured; a fifth has a materially stouter 

 shaft, though differing in no other way that I can see. 



Tibia (Plate XXXV, Fig. 6) and fibula (Plate XXXV, 

 Fig. 7). — -These bones are not very characteristically different 

 from those of either Theropleura or Dimetrodon. Both are con- 

 siderably curved away from each other, the outer border of the 

 fibula nearly straight, the inner deeply concave. 



There are also four tibialia and four fibularia which scarcely 

 differ from those of Dimetrodon, save in size; and numerous tarsal 

 and carpal bones of different kinds. Perhaps some of them belong 

 with Nothodon. 



As I have said, the differences between these bones and corre- 

 sponding ones of Dimetrodon are so striking that I cannot believe 

 that they belong with Sphenacodon, which in its skull characters 

 is scarcely distinguishable from that genus. It is for this reason 

 that I refer them provisionally to Ophiacodon, though, it must be 

 confessed, the entire absence of long-spined vertebrae in the collec- 

 tion coming from this bone-bed throws much doubt over their 

 determination, as well as the affinities of Sphenacodon. 



VARANOSAURUS 

 Broili, Paleontographica, LI, 71, 1904; Case, Pelycosauria, 20, 79, 1908. 



Varanosaurus brevirostris, n. sp. Plates I-XIII. 



The genus Varanosaurus was defined by Broili from a con- 

 siderable part of a skeleton found on West Coffee Creek, Texas, 

 which he referred to a new species, V. acutirostris. 1 The type 



1 Broili, op. cit., p. 71, PL X, Fig. 2; PI. XI; PI. XII, Figs. 22-32; Case, op. cit., 

 PI. II. 



