Dr. A. Giinther on Siamese Reptiles. 267 



larger and more distinctly keeled towards the belly ; no large scales 

 intermixed with the small ones, only a few appear to be a little 

 larger than the rest. Tail slightly compressed at the base, surrounded 

 by rings of oblong, keeled scales. Throat expansible ; a very slight 

 fold before the shoulder, 



4. DlLOPHYRUS MENTAGER. 



Dorsal crest not interrupted above the shoulder, interrupted above 

 the hip ; caudal crest as high as that on the back ; no large scales 

 on the side of the neck ; sides of the throat with large convex or 

 tubercular scales. 



This species belongs to the genus Dilophyrus, Gray (Catal. Liz. 

 p. 238). A high crest, composed of sabre-shaped shields, extends 

 from the nape of the neck to the second fifth of the length of the 

 tail, being interrupted above the hip. Scales on the back and the 

 sides of equal size, very small, with an obscure keel obliquely directed 

 upwards ; those on the belly smooth, on the lower side of the tail 

 rather elongate, strongly keeled. Tympanum distinct. Throat with 

 a cross-fold. Orbital edges and sides of the neck without spines. 

 Tail transversely banded with black. 



One stuffed specimen is 30 inches long, the tail occupying 21. 



5. Tropidophorus microlepis. 



Snout rather narrow and produced. Scales on the back strongly 

 keeled, the keels not terminating in elevated spines. Back of the 

 tail with two series of moderately elevated spines, the series not being 

 continuous with those on the back of the trunk. Scales of the throat 

 smooth, or very indistinctly keeled. Tail with a series of plates 

 below, which are much larger and broader than the scales of the 

 belly. Three large prseanals. A single anterior frontal (internasal)*. 



6. SiMOTES T^NIATUS. 



Scales in nineteen rows. Brownish-olive, with a brown longitu- 

 dinal dorsal band enclosing an olive-coloured line running along the 

 vertebral series of scales ; another brownish band along the side of 

 the body ; belly whitish, chequered with black. 



One loreal shield ; one anterior and two posterior oculars ; eight 



* This is the third species of Tropidophorus. The two others are : — 



1. Tropidophorus cochinchinknsis (Cuv.) : Dum. Bibr. v. p. 556. pi. 57. 

 f. 1. — Tropidosaurus montanus, Gray in Griffith, Anim. Kingd. ix. App. p. 35. 



Snout rather obtuse. Scales on the back strongly keeled, the keels terminating 

 in slightly elevated spines. Two series of moderately elevated spines along the 

 middle of the hack of the tail, the series being continuous with those on the 

 back of the trunk. Tail with a band of large hexagonal plates below ; two large 

 prseanal scales. Two pairs of anterior frontal shields. Cochinchina. 



2. Tropidophorus Grayi, n. sp- (T. cochinchinensis, Gray, not Cuv.). 

 Snout rather narrow and produced. Scales on the back as well as those on 



the tail with an exceedingly strong, lamelliform keel, elevated and spinous pos- 

 teriorly. Two series of spinous keels on the back of the tail, continuous with 

 those on the back of the trunk. Tail with rhombic scales below, which are not 

 much larger than those of the belly. Scales of the throat strougly keeled. Three 

 large pneanal scales. Two pairs of anterior frontal shields. 

 Philippine Islands. Three specimens in the British Museum. 



