CROCODILIANS, LIZARDS, AND SNAKES. 213 



In the Iguauidpe, the premaxillary is very seldom sei)arated from the 

 vomer on the palatal face. The coronoid bone is i)rodnced anteriorly 

 and not posteriorly on the external face of the ramus. The splenial 

 bone is well develo])ed, and the Meckelian is more or less roofed over. 

 The angular bone is much more developed on the external than the 

 internal face of the ramus. In these characters the IguanidsB agree 

 with the majority of the Dijiloglossa and Leptoglossa. 



In neither family are the temporal fosste overroofed with ossification, 

 nor do any of their members exhibit osteodermal plates. 



The Agamidse are restricted to the Old World. The Iguanidse inhabit 

 the New World, Madagascar, and the Fiji Islands. 



AGAMID^. 



lijuaniens Cuvier, part, Regne Anim., II, 1817, p. 29. 



AscalabotoB Merrem, part, Tent. Sj'st. Amph., 1820, p. 39. 



StelUonidw Gray, part. Am. Phil. (2), X, 1825, p. 196. 



Pnenstoidea, Draconoidea, Agamoidea Fitzinger, part, Nene Classif. Rept., 1826, 



p. 11. 

 Agamidce Gray, Phil. Mag. (2), II, 1827, p. 57. 

 Fachyglossw Wagler, part, Syst. Aiiiph., 1835, p. 141. 

 Dendrohatw emphyodontes and Uitmiva(j(e emphijodonte.s Wie<;mann, Herp. Mex., 



1834, pp. 13, 17. 

 Iguanieiis acrodontcs Dumkril and Bibron, Erp. Gen., IV, 1837, p. 375. 

 (ronyochepliaU, Calotae, Semioplion, Oc1ocr!iptae,Lophur<v, Dracones, Trapeli, SteJJi- 



ones, Lelolepidea, Phrynocephali Fitzin(;er, Syst. Rept., 1843. 

 Agamidw Gray, Cat. Liz., 1845, pp. 5, 230. 

 Agamidw Cope, Proc. Acad. Nat. Sci. Phila., 1864, p. 227. 

 Agamidw and Uromasticidw Theobald, Jonru. Linn. Soc, X, 1868, pp. 33, 34. 

 Agamidrv Boulenger, Ann. Mag. Nat. Hist. (5), XIV, 1884, p. 119; Cat. Liz. Brit. 



Mus., 2d ed., 1, 1885, p. 250. 



The following are some of the osteological characters of this family : 

 Teeth in alveola, coossifled with them in adults (acrodont.) 

 Premaxillary generally separated from maxillopalatines by maxilla- 

 ries, small, undivided. 



Splenial small, or more frequently wanting; Meckelian groove open; 

 angular and surangular distinct, the former small on outer, much pro- 

 longed on inner face of ramus. Ooronoid produced posteriorly on 

 external face of mandible. 



An examination of twelve genera of this family shows that the vis- 

 ceral characters agree in general with those of the Iguanidte. The 

 liver is bilobate posteriorly in Calotes and in Uromastix; more conspic- 

 uously so in the latter, where the posterior border is deeply emargiuate. 

 In Amphibolurus barhatus and MegaloehUus auritus the border is trilo- 

 bate; in the former the middle lobe is more than usually distinct and 

 lies superior to the right and left lobes. In these two species also the 

 ventral mesentery is bifurcate to the. proximal end of the liver. In the 

 A. barhatus the cystic mesentery is short, and the urinary bladder is 

 rudimeutal. In MegaloehUus the small intestine is rather short. The 



