FROGS OF SOUTHEASTERN BRAZIL — COCHRAN 331 



gray dots around the chin; lower sides of tarsus and sole of foot dark 

 brown. 



Variations. — Occasionally a wide white middorsal stripe is present. 

 The brown dorsal spots then appear to be paired on each side of the 

 white stripe, and as three or four series of these are present, the pattern 

 suggests a checkerboard. 



Remarks. — This species closely resembles L. mystaceus. The 

 characteristics that separate them seem to be quite constant, however; 

 the two prominent dorsolateral folds extend from tympanum to groin 

 in mystaceus, while sibilatrix has four and often six folds, the more 

 dorsal ones beginning behind the shoulders. The former has a longer 

 snout with a straighter labial border and a more rounded tip, while the 

 latter has a shorter snout, convex in outline, and distinctly pointed 

 at the tip. The coloration is also partly diagnostic, since mystaceus 

 does not have the wide light dorsal stripe frequently found in sibilatrix. 

 The dark dorsal spots of the latter are also smaller and more con- 

 spicuous than in mystaceus, while the dark interocular triangular 

 patch, entire in mystaceus, is broken in sibilatrix whenever a light 

 dorsal stripe occurs. 



The eggs of sibilatrix are deposited in a mass of foam in holes near 

 water. The young emerge and may be found in adjoining fields. The 

 call of the male is a long distinct whistle, rapid at first, then slow, 



as • ■. It is found living in many of the same 



regions as its allies mystaceus and mystacinus. 



Specimens examined 

 BRAZIL: 



Amazonas: "Lower Amazonia," USNM 28924^5, 28967-8, 28970-1, 28973, 

 Steere. 



EspfRiTo Santo: ltd, IB 131. 



MiNAS Gerais: Janudria, IB 412. Lag6a do Curralinho, near Lassance, 

 USNM 98210, Cochran, Dias, and Venancio, Mar. 22, 1935. Pirapora, 

 USNM 98268-71, Cochran, Dias, and Venancio, Mar. 23, 1935 Piraporinha, 

 USNM 98548, Cochran, Dias, and Venancio, Mar. 23, 1935. Rio Pandeiro, 

 IB 277, 475-6, 479-80, 485-6, 533-4, 536. 



Rio de Janeiro: Campo Bello near Montserrat, USNM 96944-5, Zikan, 

 1923-4. Entre Rios, USNM 97218, Venancio, December 1922. Fazenda 

 Niagara near Barreira, ZSBS 266, Bresslau, December 1913. Guapi, 

 Teres6polis, USNM 97678-9, Sandig, 1935. Sacco Sao Francisco, near 

 Niteroi, USNM 99119, Venancio, Feb. 14, 1935. 



Rio Grande do Sul: Santa Maria, IB 615. 



Santa Catarina: Sao Bento, USNM 97174r-5, Behr, 1915 (identity question- 

 able) . 



Sao Paulo: Capital, IB 178. Emas, DZSP 2422, 2432, 2437, 2440-2, 2489. 

 Vanzolini and Bokermann, December 1947. SSo Paulo, IB 600. 

 TRINIDAD: USNM 12163. Port-of-Spain, USNM 102392-400. 



