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 9 



of posterior extremities 2 5 



Hyla agrestis. Mihi. 



Plate XIX.— Fig. 3. 



Capite brevi. Oculis subprominentibus . Tympano mediocri circulari. Lingua sub- 

 rotunda, poslice libera, antice angustatd. Dentibus palatinis in fasciculis binis, 

 pauld separatis, ad marginem postico-interiorem narium posteriorum. Dorso granu- 

 loso. Guld plicald. Digitis anticis ad basin tantum, posticis usque ad phalanges 

 penultimas palmatis. Supra viridis, linea alba laterali, femoribus poslice atque 

 lateribus abdominis, albis, nigro-maculatis . 



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 a line with the hinder margin of the posterior 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 



