92 
The subtympanal scale is absent in one specimen only, and as 
the gular sac is both much smaller and much less brightly 
colored in the same individual, it is at least possible that these 
may be sexual characters. 
GoNYOCEPHALUS IJ pILOPIIUS? 
Lophyrus dilophus, Bum. & Bibr ., Ilerp. Gen. iv. p. 419, pi. xlvi. 
Snout rather pointed, shorter than the diameter of the orbit ; 
nostril lateral, much nearer to the tip of the snout than to the eye; 
canthus rostralis and supraciliary edge projecting ; tympanum 
distinct, round, not nearly so large as the eye-opening ; upper 
head scales sin all, keeled, more strongly so on the supraorbital 
region, along the inner margin of which there is a semicircular 
row of enlarged scales : an oval band of enlarged raised scales on 
the middle of the snout, the keeling of which is radiate; the 
occipital region is bounded on all sides except the anterior by a 
raised ridge ; it is arcuate behind, and similar in shape and size 
to the upper surface of the snout, and the enlarged occipital scale 
is situated near its hinder margin ; most of the scales between 
the orbit and the tympanum, and an interrupted row round the 
tympanum much enlarged ; a row of enlarged keeled scales 
bordering the upper labials ; eleven or twelve upper and a similar 
number of lower labials ; a row of enlarged scales from the mental 
shield to beyond the angle of the mouth, anteriorly smooth and 
forming a suture with the first four lower labials, posteriorly 
strongly keeled and separated from those shields by from one to 
four rows of smaller scales. Gular sac large, with like large 
foliate scales in front ; gular scales small, much smaller than the 
ventrals, strongly keeled, with a few scattered enlarged ones 
intermixed on the sides. Nuchal crest not continuous with the 
dorsal, formed of four large blunt foliaceous scales, with a few 
much smaller and more pointed ones in front, and with several 
rows of enlarged lateral basal scales of unequal size, the anterior 
of which are keeled, the posterior smooth ; its height is five-ninths 
of the length of the snout ; dorsal crest formed of equal sized 
foliaceous scales, similar to, but a little lower than, the nuchal 
crest. Dorsal scales small, strongly keeled, the points being 
directed upwards and, in a lesser degree, backwards ; enlarged 
pyramidal scales on the sides, forming irregular vertical series ; 
ventral scales much larger than the dorsals, strongly keeled. 
Limbs with keeled scales of unequal size ; fourth finger a little 
longer than the third ; the adpressed hind limb reaches beyond 
the snout. Tail strongly compressed, with an upper scries of 
enlarged scales similar, and on its anterior half equal in size, to 
those forming the dorsal crest ; all the caudal scales keeled, the 
inferior series largest and elongated, with their keels terminating 
in a strong sharp spine ; tail of moderate length, with an abruptly 
truncated tip, once and two-thirds of that of the head and body. 
