18 M. G. A* Boulenger on little-known 



none. Head small ; snout considerably longer than in P. 

 biligonigera, at least as long as the diameter of the orbit ; 

 nostril nearer the tip of the snout than the eye ; interorbital 

 space as broad as the upper eyelid ; tympanum hidden. Fin- 

 gers slender, first not extending beyond second ; toes slender, 

 elongate, with a slight rudiment of web ; subarticular tubercle 

 well developed ; tarsus with a small conical tubercle near the 

 middle of its posterior face ; two small prominent oval meta- 

 tarsal tubercles, smaller than in P. biligonigera ; a narrow 

 dermal fold connects the tarsal and inner metatarsal tubercles, 

 as in P. falcipes *. The hind limb being carried forwards 

 along the body, the tibio-tarsal articulation reaches the eye or 

 a little beyond. Skin smooth, with slightly marked short 

 glandular folds. Brown above, with more or less distinct 

 darker markings on the back j a dark transverse bar between 

 the eyes ; a blackish streak from the tip of the snout to the 

 eye ; a blackish oblique band, widening gradually, from the 

 eye to the middle of the side ; groin generally with a round 

 black light-edged spot, which is entirely concealed when the 

 hind limb is folded against the body ; hind limbs with dark 

 cross bars ; lower surfaces whitish, more or less mottled with 

 brown. Male with two external vocal sacs. The largest 

 specimen measures 30 millim. from snout to vent. 



Numerous specimens, one only being adult, were obtained 

 from Dr. v. Ihering, who collected them in the province of Rio 

 Grande do SuL Three other specimens (lc?,2?) with- 

 out locality are in the British Museum. 



There can be no doubt that this is the frog referred with 

 hesitation to Gomphobates notatus, R* & L., by Dr. Hensel. 

 He describes very accurately the coloration, but does not give 

 the structural characters, remarking, however, that he finds 

 not unimportant differences between his specimens and that 

 figured by the Danish authors. Afterwards f Prof. Peters 

 expresses the opinion that Dr. Hensel's determination is cor- 

 rect, and that the specimens are only a colour variety. The 

 differences, however, are striking, as may be seen by the cha- 

 racters here given. The general proportions are considerably 

 more slender, much like those of Paludicola Olfersii (Mar- 

 tens) |, from which P. gracilis may be easily distinguished by 

 its very distinct tarsal tubercle and tarsal fold. 



# The British Museum has obtained several specimens of this frog from 

 Dr. v. Ihering. 



t Mon. BerL Acad. 1872, p. 223. 



% Cf. Peters, Sitzb. Ges. nat. Fr. BerL 1882, p. 62. This species is 

 known to me from one specimen, which I owe to the kindness of Prof. 

 Peters. 









