CROCODILIANS, LIZARDS, AND SNAKES. 613 



ijuxtaposed or imbricate, usually smaller tliau the veutrals, which form 

 longitudinal and transverse series. (Bouleuger.) 



I have only had opportunity to examine the visceral anatomy of the 

 genera Tachi/droDtiis, Laccrta, and EremidH. These possess a urinary 

 bladder and a corpus adiposum, which projects freely into the abdomi- 

 nal cavity. The alimentary canal displays no colon. The liver is not 

 elongate, and exhibits a small middle (third) lobe of the posterior 

 border. Its right lobe exhibits a recurved lobe from its extremity, 

 which points posteriorly next the body wall. The mesenteries are of 

 the usual or normal type of the order. 



They inhabit Europe, Asia, and Africa; are absent from Madagascar, 

 and most abundantly represented in Africa, with but few in the East 

 Indies. 



1 have examined the hemipenis in the genera Lacerta, AcantJw- 

 iJactylKSj and Laiastia. They are bifurcate or bilobate. Vn each divi- 

 sion and proximad to it is an oval area with transverse laminre and 

 surrou)ided by a welt. In Aeanthodactyhis one of the areas is marked 

 by longitudinal folds. 



SYNOPSIS OF THE GENERA. 



I. Frontal plate separated from tlie interparietal by a pair of frontoparietals; tail 

 not much depressed. 

 A. Nostril above the first labial, from which it is separated, if at all, by a nar- 

 row rim; transparent palpebral disk, if present, considerably 

 smaller than the eye. 



1. Inguinal but no femoral pores Tachndromus Daudin. 



2. Femoral pores. 



a. Ventral plates keeled Poromera Bonlenger. 



i. Ventrals smooth. 



Collar well marked; dorsal scales mn eh smaller than caudals; digits 



not fringed laterally, not keeled interiorly Lacerta Linnifus. 



Collar well marked ; dorsal scales nearly as large as caudals. strongly 

 imbricate; digits not fringed laterally, not keeled inleriorly. 



Jlgiroides Bibron. 

 Collar very indistinct or absent; digits not fringed laterally. 



I'sammodromiis Fitziuger. 

 Collar well marked ; digits not fringed laterally; keeled iuferiorly. 



Lataatia Bedriaga. 

 CoUnr more or less distinct; digits fringed laterally and keeled. 



Acanthodacfylus Wiegmann. 

 A A. Nostril well separated from the labials. 



1. Lower eyelid scaly or with a small transparent disk. 



rt. Digits smooth or indistinctly keeled interiorly, not fringed laterally. 



CoUnr well marked; ventral plates keeled (lastroplioUs Fischcsr. 



Collar absent; dorsal scales large, imbricate, strongly keeled. 



Tropidosa ura Fitzinger. 

 Collar well marked; dorsal scales small; ventral plates smooth. 



Xucras Gray. 

 h. Digits distinctly keeled interiorly, not fringed laterally. 



Collar al)scnt; dorsal scales large, imbricate, strongly keeled. 



JchtiofropiH Peters. 

 Collar more or less distinct; dorsal scales amiill.. Eremias Wiegmann. 



