FOSSIL VARANIDAE AND MEGALANIDAE. 
453 
whilst absent in other forms ( Agamidae , Lacerta, Zonurus, Egernia &c.) 
and which are, laterally viewed, situated under and somewhat backwards 
from the foramen ovale, I designate as tubera p 1 e u r o c c i p i t a 1 i a 
(mihi). They might have been perhaps stronger developed in Mega- 
lania than indicated by the reconstructed outlines visible on the drawings 
accompanying Sir R. Owen’s paper. Between the proc. parotid and the 
tubera pleuroccitalia a semilunar shallowness is present (the concave part 
of which is turned upwards, excavating the most basal part of the proc. 
parot.), bearing on its inner and upper part (in the proximity of the pars 
condyloidea lateralis) the vagal foramina (Textfig. 29a). 
c f d 
Fig. 30. Dentary fragment of f Meijalania prisca Ow. (Type of Œotiosurus dentatus 
Off.») — Nat. size. — Cuddie Springs. — a — internally, 6 = externally viewed, c = upper 
view, d — lower view (showing the sulcus pro cartilagine Meckeli), e = end view, / = 
vertical section of mandible and tooth-base. — From Sir R. Owen, in Phil. Trans., 
Voi. 175, PI. 12, Figs. 1, 2, 3, 6, 4, 5. 
3. Otosphenoid. Ala otosphenoidea strongly developed (Textfig. 
29), similarly as in Varanidae; crista otosphen. well marked, prominent ; 
sulcus venae iugularis deep. 
4. Basioccipital broad, hollow on its lower surface, with 
prominent tubera sphenoocipitalia ; pars condyloidea medilais broad, 
about twice as broad as one pars condyloidea lateralis, separated from the 
latter ones by well discernible sutures. 
5. Basisphenoid strongly fractured at its anterior part ; 
processûs pterygoidei broken, being discernible only in their basal portion ; 
if basisphenoid takes part in the formation of sphenooccipital tubera or 
