194 Lacertidas. 



Head-shields normal, but occipital sometimes absent. 

 Nostril pierced between two or three nasals, well sepa- 

 rated from the first upper labial. Lower eyelid distinct 

 from the rudimentary upper, with a very large trans- 

 parent disc. Collar absent, indicated only on the sides. 

 Dorsal scales rhombic, imbricate and strongly keeled, 

 large. Ventral jDlates imbricate, smooth. Digits com- 

 pressed, with sharply keeled lamellaa inferiorly. Femoral 

 pores. Tail long, cylindrical. 



India and Ceylon. 



The parietal foramen is present and there are no pterygoid teeth. 



Apart from the large palpebral transparent disc and the keeled 

 subdigital lamellae, this genus agrees very closely with Tropidosaura, 

 and the condition of the shields surrounding the nostril in G. jerdonii 

 is exactly the same as in that genus and in Nucras. It is therefore 

 highly probable that Cahrita was derived from extinct Northern 

 members of the genus Niicras, after passing through forms more or 

 less similar to Tropidosmira. The type species, C. leschenaultii, shows 

 a higher grade of evolution, so far as the nasal shields are concerned, 

 these having assumed the condition characteristic of the typical 

 Eremias and of IcJmotrojns. These views on the phylogeny of this 

 species, as well as of Psammodromus, ai'e based on the assumption 

 that the arrangement of the shields bordering the nostril is more 

 primitive in Nucras than in Lacerta, as explained above vol. i, p. 31. 



The two species of this genus are easily distinguished by the 

 following characters : 



Nostril between an upper and a lower nasal, followed by one or two post- 

 nasals; anterior vipper labials projecting, angular ; occipital present; 42 to 52 

 scales and plates roiind middle of body ; 24 to 27 tx-ansverse series of ventral 

 plates ; 19 to 25 gular scales in a straight line ; 18 to 24 lamella:' under the 

 fourth toe C. leschenaultii, M.-Edw., p. 194. 



A single nasal, followed by two superposed postnasals ; occipital absent (very 

 rarely present) ; 26 to 30 scales and plates round middle of body ; 19 to 28 

 transverse series of ventral plates; 14 to IS gular scales in a straight line; 17 

 to 19 lamellse under the fourth toe .... C. jerciojiii, Bedd., p. 197. 



1. CABEITA LESCHENAULTII. 



Lacerta leschenaultii, M.-Edw. Ann. Sc. Nat. xvi, 1829, pp. 80, 86, 

 pi. vi, fig 9. 



