46 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
from the eye backwards to the arm, including the tympanum, and this fascia is bordered 
beneath by a white line. The thighs and legs are barred and spotted with black. The 
under parts are yellowish white, excepting under the lower jaw, where it is finely mottled with 
black and white. 
I received the name of this species from Mons. Bibron, who had, I believe, 
applied it to specimens in the Paris Museum. It was taken by Mr. Darwin at 
Maldonado, lurking under a stone, and at Rio Janeiro on palm-trees. 
DIMENSIONS. 
In. Lin. 
Length of the head and body 1 6 
of anterior extremities 0 9 
of posterior extremities 2 5 
Hyla agrestis. Mild. 
Plate XIX. — Fig. 3. 
Capite hrevi. Oculis subprominentihus . Tympano mediocri circulari. Lingua sub- 
rotunda, postice libera, antich angustatd. Dentibus palatinis in fasciculis binis, 
jKiuld separatis, ad marginem postico-interiorem nariuni posteriorum. Dorso granu- 
losa. Guld plicata. Digitis anticis ad basin tantimi, posticis usque ad phadanges 
penultimas pahnatis. Supra viridis, linea alba laterali, femoribus postice atque 
lateribus abdominis, albis, nigro-niaculatis. 
Habitat, Maldonado, in grassy fields. 
Description. — Head short, thick, the two sides of the muzzle approaching each other at a rather 
acute angle, rounded at the extremity. Eyes rather large and prominent. Tympanum 
circular, of moderate size, and very distinct. Tongue entire, rounded, and free behind, 
narrowed, and almost angular in front. Palatine teeth in two oval parcels separated by a very 
small interval, and placed on aline with the hinder margin of the posArmr nares; the whole of the 
back covered with extremely small granules ; a slight fold or elevation of the skin commencing 
above the posterior margin of the tympanum, and extending backwards just above the arm, in 
front of which it is met by a more considerable one which crosses the throat from side to side ; 
the under parts covered with large granules ; fore feet with the toes palmated only at the base ; 
hinder ones palmated to four-fifths of the length. 
The colour of this beautiful species is thus given by Mr. Darwin : — “ Above 
emerald green, beneath white ; a silvery white stripe bordered beneath with a 
very narrow black line, extends from the corner of the eye, along the side, to the 
