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minuté granuîato. Seriebus duabas squamarum supralabialium. Femorum facie
postei'iore partim gx'anulosci, partim squamis minutis imbricatis tectâ.
Proctotretus ’Weigmarmil, Bibr. 1. c. p. 284.
Habitat, Northern Patagonia and La Plata.
D e s c m p t io n .— H e ad ra th e r short, covered with numerous slightly ra ised scales, n o t c a rin ated nor
im b ric a te d ; snout ra th e r obtuse an d slightly ro u nded, nostrils semicircular. Two series o f
very small scales betwe en th e labial scales an d th e orbit. E a r o f moderate size, th e an te rio r
margin furnished merely with m inute g ran u la r scales. Scales o f th e temples fiat an d smooth.
F o ld on th e sides o f th e neck distin c tly marked, an te rio rly bifurc ated ; th e rema in d er som ew
h a t waved. Sides o f th e neck g ra n u la ted scales o f the whole o f th e u p p e r an d back p arts
o f th e b ody an d ta il o f moderate size, th e ca rina little elevated an d th e p o in t b u t slightly
prominent. T h e scales o f th e inferior p a rts o f th e neck an d b ody arc smooth, polished, and
imbricated, those towards th e sides o f th e neck min u te ly emarginated. T h e scales o f th e
limbs resemble those o f th e b o d y ; those o f th e u p p e r surface b e in g c a rin ated an d those
b en e a th smooth. T h e posterior face o f th e thighs is gene rally covered w ith g ra n u la r scales,
b u t th e re is on this p a r t n e a r th e tail, a d is tin c t p atc h o f imbricated scales resembling those
o f th e inferior surface o f th e thighs, a cha rac ter b y which th is species m ay a t once be
distinguished fiom all others. T h e a n te rio r extremity placed aga inst th e aide reaches ab o u t
two-thirds o f th e diiSmce towards th e g ro in ; th e posterior e x trem ity reaches forward to the
shoulder.
CoLotiB.—T h e back an d sides are brownish gray, with a yettow long itu d in a l b a n d on each side of
th e back, sepa rating transverse black o r dark brown b an d s o f various size an d form ; an d th ere
is in most on ea ch side a smaUer in te rru p te d yellow ban d . T h e u n d e r p arts gene rally o f a
yellowish white, in some individuals sparsely d o tted w ith black. Mr. D a rw in says o f some
individuals o f this species tb a t th e y have “ an orange-coloured gorge, a n d fa in t stripes o f blue,”
also o ash-grey w ith d a rk brown marks an d specks o f orange an d blue. ’
DIMENSIONS.
Inches. Lines.
Length of the head.................................. 0 5
of the body ............................. 1 5
of the tail .................................. 2 2
T o ta lle n g th .... 4 2
Length of anterior extremity 1 1
of posterior extremity................ 0 8
This species was found by Mr. Darwin a t Bahia Blanca and a t Rio Negro,
on the northern confines of P atagonia, and at Maldonado, near the mouth of the
Rio Plata.
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