6 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
whole under surface is of a whitish colour, sometimes having a slight tint of orange towards the 
posterior parts, marbled with black. 
Var. C. In this variety the general colour is dark brown, and the yellow or green longitu- 
dinal lines which characterize the former varieties are but slightly marked ; but the black spots 
unite and form irregular transverse bands. 
DIMENSIONS. 
Inches. Lines. 
Length of the head 0 6 
of the body I 8 
of the tail 4 6 
7 0 
This specimen very macli resembles in its more tangible characters, the Pr. 
tenuis ; from which, however, it differs totally in the colouring, and in some mea- 
sure also in the general form, which is more thick and robust. 
Found in Chile by M. Gay, from whence I also received specimens from Capt. 
King, and other sources. — “ Valparaiso.” Mr. Darwin. 
Proctotretus Bibronii. N.S. 
Plate III. — Fig. ] . 
Capite squamis Icevibiis, suhconvexis ; auribus ovalibus, margine anteriore unidentato ; 
squamis temporum colliqiie rotundatis Icevibus imbricatis ; colli minimis ; serie unica 
squamarum supralabialium ; squamis doi'si rhomboideis, carinatis, postice acumina- 
tis ; abdominis squamis omnibus intcgris ; femorum facie posteriori omnino 
granulosa. 
Habitat, Port Desire. Mr. Darwin. 
Description. — General form resembling that of Pr. pictus and cyanogaster. Head moderately 
short, obtuse, covered with rather large slightly convex scales ; a single row of scales between 
the labial and the orbitar. The anterior margin of the ear has a single tooth. The temples 
and the sides of the neck are covered with imbricated scales, which have no carina — those of 
the neck, especially those on the fold of the skin are smaller and more raised than the others. 
The scales of the back are rather large, rhomboidal, with a distinct carina, terminating in a 
point. Those of the abdomen and sides are all of them entire at the mai’gin. The posterior 
surface of the thighs is wholly granular. 
The only specimen obtained being a female, the number of pre-anal pores is not known. 
The general colour of this species is brownish grey ; a black longitudinal line runs down 
the middle of the back and tail. There are two scries of black spots on each side, and a 
