FOSSIL VARANIDAE AND MEGALANIDAE. 
899 
in the geographical distribution of Ophisaurus pannonicus (Form.) hi¬ 
therto known from Polgárdi (County of Fehér). 1 
8. Caudal vertebrae. (Pl. II, Figs. 11—20.) The caudal 
vertebrae are also characterized by great massiveness and a narrow neural 
canal, though the latter marking being less apparent than in the 
cervical and dorsal vertebrae. Crista medialis and cristae laterales pre¬ 
sent, and well observable ; the vertebrae resembling in shape those of 
V. griseus, though larger and robuster, and bearing, as mentioned above, 
a narrower neural canal. Centre in first postsaeral vertebrae shorter and 
broader, in following ones narrower, and elongate. Attachement-surfaces 
of loosened chevron-bones distinct, roundish in first postsaeral vertebrae, 
oblong in the after ones. Ball projecting, roundish in first postsaeral ver¬ 
tebrae, which are also provided with a subrotund, rather deep cup, whilst 
in the following vertebrae the strongly projecting ball and deep cup are of 
ellipsoid shape ; no terminal vertebrae of tail have been found, one excepted 
(from the upper Quarry of Csarnóta) classifiable as belonging to the proxi¬ 
mal part of about the ultimate third of tail. Two strongly marked long crests 
ending in the «talons» of chevron bones present in all caudal vertebrae 
(cristae inferiores vertebrarum caudalium mihi), the very first postsacral- 
ones excepted, where these bony elevations are but very faintly marked, 
the «talons» of the chevron-bones rising hereby more abruptly from lower 
part of centre. The cristae infer, limit a well-marked tolerably broad furrow 
(sulcus medialis mihi). A morphological difference between V.;griseus and 
V. marathonensis seems to consist of the cristae inferiores being less prominent 
in the latter one, lending thus a more complete cylindrical shape to the 
centre, and being more parallel in their course, whilst in V. griseus 
a slight strangulation may be observable in the middle region. No foveae 
paraglenoideales. Processûs transversi broken in most specimens of these 
fossil vertebrae, and when present, incomplete, the distal portion missing, 
thus not permitting the statement of their length. In the first postsaeral 
vertebrae the fracture indicating the proc. trans, prove of their having 
been, in this portion, somewhat bent backwards, or at least at right angles 
1 Regarding the defective technique of Bolkay’s drawing two points must be 
yet taken into consideration. 1° On account of the unpe;.fect shading a tolerably long 
and deep sulcus connectens seems to extend from the front outlet of the spinal canal 
towards the wide lateral portion of the arcus vertebrae, which in reality is not the case. 
2° The arched part between proc. obi. ant. and proc. spinosus, although in good condi¬ 
tion, appears to be fragmentary, and. is meant to represent, in foreshortened view, 
the upper part of proc. obi. post. — My remarks on Ophisaurus have only been made 
incidentally, from a historical point of view, since my wife is now examining this ques¬ 
tion more closely in her Monography on fossil Ophisaurus, to be published hereafter. 
