Mr. G. A. Bouleuger on a new Iguanoid Lizard. 85 



Discoglossus from that of other Disco glossidaj * ; but there is 

 a character in the maxillary which is very striking and which 

 I think I can discern in the fossil, although I am not quite 

 sure about it — that is, this bone sends up a broad process which 

 joins the anterior limb of the T-shaped squamosal, whilst in 

 Alytes and Bomhinator the maxillary tapers posteriorly 

 without sending off any sort of process. 



XI. — Description of a new Genus of Iguanoid Lizards. 

 By G. A. BOULENGER. 



Aptychol^mus. 



Tympanum distinct. Body cylindrical ; no dorso-nuchal 

 crest. Dorsal scales equal, juxtaposed, keeled; lateral scales 

 granular ; ventral scales imbricate and keeled. Head-scales 

 small ; no gular fold, no gular sac. No femoral or prajanal 

 pores. Digits subcylindrical, with smooth laraellse below. 

 Tail very long, cylindrical. Lateral teeth tricuspid; ptery- 

 goid teeth present. No sternal fontanelle. Abdominal ribs. 



This genus is allied to UrostrophuSj D. & B., and Aniso- 

 lepis, Blgr., but differs from both in the absence of a gular 

 fold and in the dorsal lepidosis. 



Aptycholcemus longicauda. 



Head rather small, body elongate. Nostril lateral, near 

 the end of the snout ; ear-opening small, suboval, oblique. 

 Upper head-scales rather small and smooth, smallest on the 

 supraocular region, largest on the snout ; occipital slightly 

 enlarged, larger than the ear-opening -, upper labials eight or 

 nine, very low. Anterior gular scales small, equal, granular, 

 keeled. Dorsal scales mostly hexagonal, strongly keeled, 

 forming about twelve longituilinal series,, passing gradually 

 into the small granules which cover the sides. Ventral scales 

 much larger than dorsals, strongly keeled, shortly mucronate, 

 imbricate, in 16 to 18 longitudinal series ; the keels forming 

 straight longitudinal lines. The adpressed hind limb reaches 

 the shoulder, or halfway between the fore limb and the ear. 

 Tail at least three times as long as head and body, covered 



* The mandibles of the Discoglossidae and Pelobatidaj differ from those 

 of all other European frogs in the absence of sympliysial or mento- 

 meckelian bones. 



