th e labial scales, a n d th e long infra -orbital plate is a single series o f ro u n d e d scales.* T h e scales
o f th e temples are ra th e r large, somewhat ro u n d ed , slightly imbricated, an d a few o f the
p osterior ones having th e vestige o f an obtuse cariua. T h e e a r is ra th e r small, th e an te rio r
m arg in having two slightly p rom in en t scales towards th e lower part.
T h e body is depressed ; th e tail moderately long, th ick an d slightly four-sided a t th e base,
becoming much smaller and ro u n d towards th e middle. T h e scales o f th e sides o f th e neck
are small an d g ran u la r ; those o f th e u p p e r p arts o f th e body small, rhomboidal, ro u n d e d
posteriorly, loose, mu ch imbricated, an d with an extremely low an d inconspicuous carina.
T h e y are a rranged in ab o u t twenty-two long itu d in a l series. Those o f th e sides are larg e r an d
q u ite smooth. T h e scales o f th e whole u n d e r p a r t o f th e th ro a t a n d belly are rhomboidal,
smooth a n d m u ch imbricated ; a very few towards th e sides o f th e abdomen are slightly notched
a t th e apex. T h e u n d e r surface o f th e a n te rio r an d th e h in d e r surface o f th e posterior e x tre mities
are covered w ith very fine g ra n u la r scales ; those o f th e u p p e r surface o f th e members
b e in g rhomboidal, smooth, b u t slightly c a rin ated an d obtuse. T h e tail is covered with small
rhomboidal scales which are considerably imbricated a n d d istin c tly carinated. T h e scales o f
th e u p p e r surface o f th e toes are smooth ; those on th e ir sides u n i-ca rin ated , an d those ben e ath
tri-c a rin a te d an d broad.
T h e g en e ral colour o f th e u p p e r p a rts is a yellowish grey, with black markings, which have
somewhat th e cha rac ter, as Mons. B ibron observes, o f Arabic le tte rs . O n th e neck a n d back
these markings are disposed in four long itu d in a l serie s; a n d th ere are small lin e a r markings on
th e u p p e r p a r t o f th e shoulders a n d thighs. T h e tail is similarly marked, th e u n d e r p a rts are
whitish, with brown lines a n d spots.
DIMENSIONS.
Inches. Lines.
Length of the head....................................... 0 6
of the body....................................... 1 5
of the tail ............................. 3 0
T o ta lle n g th .... 5 1
Length of anterior extremity . . . . . . . . 0 8
of posterior extremity ................. 1 2
This species is not found amongst the reptiles obtained by Mr. Darwin, but as
it has never been figured, it appeared very desirable th a t this opportunity should
not be lost. I am indebted to the great kindness of my friend M. Bibron for the
loan of the only specimen which I have seen, and from which the accompanying
figure is taken. I t formed p a rt of the zoological collections obtained by Mons.
D ’Orbigny for the French Museum.
' M ods. Bibron states that there are two series, but on examining his specimen I find a single series only.