SAURES. LACEBTID^. 375 



tail ; toes free ; tongue lengthened, slender, deeply 

 forked, and capable of great extension ; scales of the 

 tail and belly placed in smooth transverse parallel bands ; 

 tail, typically, very long, attenuated, and generally round. 



Hydrosaubus Sw. Scales separated from each other 

 by annular series of minute tubercles, and imbedded 

 in the skin ; ridge of the tail rounded or carinated ; 

 size large : analogous to the Emidosauri, or crocodiles. 



Hydrosaurus Wagler.* Tail compressed, with a cari- 

 inated ridge ; habits aquatic ; the fourth hind toe long. 



H. Niloticus. Wag. Seba, chlorostigmus Gray. GrifF. 



pi. 100. fig. 3. variegatus. White's Voy. 3. 1. 



Indicus. pi. 85. lb. 2, 3. Bellii Sw. Erpet. Gen. 35. 1. 



bivittatus. Shaw, Z. pi. 66. albogularis, Daud. iii. pi. 32. 



capensis Lac. 



Empagusia Gray. Body thicker; tail shorter, nearly 



round, with a dorsal keel ; feet short, strong ; the 



fourth hind toe not longer than the third. 



E. flavescens. Ind. Zool. ocellata Gray. RUpp. Atl. 



albogularis. Daud. iii.pl. 32. i. pi. 6. 



Odatria Gray. Tail lengthened, round, with rings of 

 keeled sub-spinous scales, and without any dorsal 

 keel ; toes rather strong and moderate : Australia. 

 O. punctata Gray. Ann. Nat. Hist. No. 5. p. 394. 



Varanus Fitz. Tail round or cylindrical, without a 

 dorsal ridge ; habits terrestrial ; feet moderate. 

 V. arenarius. Erp. Gen. iv. 471. Tiraoriensis. lb. 473. 



Heloderma Weig. Scales of the body resembling tu- 

 bercles, and not surrounded with smaller granules ; 

 tail round ; all the toes of the posterior feet inserted 

 in the same direction as the others. 



H. horridum. Wag, fas. ii. pi. 18. 



Lacerta Linn. General form long, slender, smooth ; 

 tail long, rounded, without any dorsal crests f ; head 

 small, covered on the crown with large shields; 

 throat scaly. 



. ,** Including Polydcedalus of the same nomenclator. 



t Except in Draccena, which unites this group to that of Hydrosaurus. 



B B 4 



