10 ARKIV FÖR ZOOLOGI. BAND 3. NiO 12. 



Peracca (loc. cit.) also mentions this species from the 

 same localities. 



Leptodactylus prognathus Boul. 



Ami. Nat. Hist..((j) 1. 1888 p. I<s7. 



30 specimens, 2 large and 28 small ones, from Tatarenda, 

 Bolivia, Chaco. Erland Nordenskiöld 1902. Length between 

 48 and 21 mm. 



In all the small specimens there are on the sole of the 

 foot and often on the tarsus and remaining parts of the hind 

 hmb small biit distinet tubercles, disposed in rows on the 

 foot. There is also a faint tarsal ridge on the inner si de of 

 the tarsus. In the large specimens the tubercles have disap- 

 peared. As Peracca (Boll. Mus. Zool. Anat. Torino 1897 

 N:o 274) finds the same structures in his specimens, both in 

 young and adult, it is true that they are constant, at least 

 in the young, though Boulenger does not speak of them. 



The ground-colour is bluish gray, in some brown. 



Leptodactylus bufonius Boul. 



Ann. Xat. Hist. (0) 13, 1894 p. 349. 



Five specimens from Tatarenda, Bolivia, Chaco, varying 

 in length between 27 and 55 mm. E. Nordenskiöld, 1902. 



The measurements I took of the specimens, a large male, 

 and four small specimens show a great correspondence between 

 the different ages. 



In the male the sides of the throat, where the great 

 vocal sacs are to be found, are deep black as well as the tym- 

 panic fold, which is very prominent and behind the tympanum 

 enlarged to a broad black nearly paratoid-like g] and. 



