27 
Squamata — Pythonornorpha . 
From the Chalk of Sussex and Kent have been obtained 
several examples of the snake-like lizard Dolichosaurus longicollis. 
The P leurosauridse are typically represented by Pleurosaurus, 
of the Lithographic stone of Bavaria, which is a medium-sized 
Lizard characterized by the extreme elongation of the body (in 
which there are a great number of presacra l vertebrae), and the 
skull is long and narrow, with slit- like nares. Anguisaurus and 
Acrosaurus, of the same deposits, belong to this family, but it is 
not certain that they are really distinct from the type genus. 
Sub-order 3. — Pythonomorpha. 
The Mosasauridce were carnivorous marine reptiles, fre- 
quently of great size, and ranging in time from the Upper 
Greensand to the uppermost Cretaceous beds, and having a 
Fig. 33.— Right pectoral limb of a Mosasauroid reptile, Platecarpus , sp. 
’Cretaceous strata of North America. T V nat. size (after Marsh.) 
a, scapula ; 6, coracoid ; c, humerus ; 'd, radius, and c , ulna. 
world-wide distribution. The body was much elongated ; the 
skull offers a strong resemblance to the Varanidce amongst the 
lizards, and has the nasal and premaxillse welded together ; the 
ouadrates very loosely articulated ; teeth on the pterygoids as 
well as in the jaws, and frequently ossifications in the sclerotic 
of the eye. The teeth are large and sharp, and anchylosed by 
expanded bases to the summits of the jaws. The clavicles are 
always, and the interclavicles and sacrum generally, wanting. 
Dolichosau- 
rus. 
Table-case, 
No. 12. 
Wall-case, 
No. 8, and 
Table-case r 
No. 11. 
