INVESTIGATIONS ON PARAGUAYAN BATRACHIANS. 
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the former isolate, the latter connected with the white stripe of the jaw. 
Hinder side of thighs marbled with black and white, but the white spots 
near the lower edge smaller and arrenged in a rather indistinct longitu¬ 
dinal row. The cross-bars on the middle surface of the limbs interrupted 
with violet-rose. Throat very finely punctulated with brown, belly and 
other parts white. 
It is known that Hensel observed a brown and blue or blue and 
grey colour on the specimens collected by him in the forests of Rio Grande 
do Sul.* I think that this blue colour, which perhaps is changed into 
violet-rose through the influence of the spirit, could be regarded as 
the nuptial-dress of the male, like our Rana arvalis Nilss. It is 
true that all (10) of Hensel’s specimens bear the same colour and it 
could not be assumed that they all were males, it is striking, however, 
that in the following species the male only is rose coloured. It is perhaps 
the same case with Leptodactylus rhodo notus Gthr.,** which differs from 
Leptodactylus mystacinus Burm. — according the descriptions — only 
by the absence of the ventral discoidal fold and the heart-shaped tongue. 
9. Leptodactylus mystaceus Spix. 
(PI. XIII, fig. 12.) 
! Rana mystacea Spix, Spec. Nov. Testűd, et Ranarum, 1824, p. 27, tab. Ill, 
fig. 1 *** (sec. spec. typ.). 
Leptodactylus poecilochilus Cope, Proc. Ac. Nat. Sc., 1862, p. 156; Boulenger, 
Cat. Batr. Sal., 1882, p. 243 ; Peracca, Boll. Mus. Torino, X, 1895, p. 27. 
A young male (length 31 mm.) and a young female (length 37*5 mm. 
from snout to vent). 
Habit of a slender Rana. Tongue large, oval, slightly nicked behind. 
Yomerine teeth in two slightly arched series behind the choanae, close 
together and laterally extending below the centre of the latter. Head 
depressed, as broad as long, or a little longer than broad. Snout subacu- 
* Arch. f. Naturg., 1867, p. 126. 
** Proc. Zool. Soc. of London, 1868, p. 481, tab. XXXVII, fig. 1. 
*** In the denomination of Spix’s figures the number 1 stands erroneously 
beside « Rana pagypus juv.», it must stand by « Rana mystacea mas.» It is a mistake, 
if Peters asserts (Monatsber. Akad. Berlin, 1872 [1873], p. 199) that Spix’s both 
specimens, exposed on the plate III by the figures 1 and 3 as Rana mystacea , 
belong to « Rana (Cystignathus) typhonia D au din», but only the latter (fig. 3) 
can be drawn to this species, while the former (fig. 1) represents quite a different 
one and is the type of Spix’s Rana mystacea , which species must be restituted in¬ 
stead Leptodactylus poecilochilus Cope. 
