Squamata Ophidia. 



25 



armour of bony dermal scutes. The limbs may be adapted for 

 walking on land, or modified into paddles for swimming. In 

 the skull the proximal end of the quadrate bone is more or less 

 movably articulated ; the lower temporal arcade is wanting ; 

 the post-orbital is generally fused with the post-frontal the 

 palate is more or less open, the pterygoids being nearly always 

 separated by an interval from one another, and the premaxillae 

 are frequently united. The vertebrae are generally pvoccelous 

 (concave in front), although more rarely they are amphiccelous 

 (bi-coneave). True abdominal ribs are never developed. The 

 carpus has but a single centrale, and the precoracoid process is 

 often well marked. 



SUB-ORDER 1. Ophidia (Serpents). 



Serpents are rarely met with in a fossil state, but a few Serpents. 

 such remains have been obtained from the Tertiary rocks. The Table-case, 

 earliest Ophidian represented in the Collection is the Palceophis No * 3 * 



Paleeophis. 



FIG. 29. Vertebrae of Palceopliis typhous (Owen), from the Lower Eocene, Sheppey. 

 A. haemal; B, anterior; and c, left lateral views of a trunk vertebra, wanting most 

 P -.""" of the neural spine ; zs, zygosphene ; c, costal articulation. 



toliapicus, a serpent about 12 feet in length, obtained from the 

 London Clay of Sheppey ; from the Middle Eocene of Brack- 

 lesham we have a still larger form, the Palceophis typhceus, a boa- 

 constrictor-like snake, considered to be marine, that attained a 

 length^of 20 feet, and also a smaller species, P. porcatus. 



c 



FIG. 30. (A) Haemal, (B) Anterior, (C) left lateral views of a trunk-vertebra of 

 Paleryx rhombifer (Owen), from the Eocene Phosphorites of Caylux, France. 

 c, costal articulation; c, zygosphene. 



The Upper Eocene sands of Hordwell have yielded numerous Paleryx. 

 vertebrae of snakes, but of a much smaller size, namely, Paleryx 



