260 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



distinguished. S. f. frontalis has the tail reddish brown and the 

 imderparts distinctly gray. S. spixi, while resembling frontalis in 

 color of the undersurface, has the tail plain brown, not decidedly 

 rufescent, and, in addition, usually may be told by the lack of gray 

 across the forehead, as the rufescent crown cap extends to the base 

 of the bill. S. a. albescens, like spixi, has a brown tail, but is dis- 

 tinctly whiter below than either frontalis or spixi. 



Doctor Oberholser has separated a form of spixi from ConchitaSy 

 Buenos Aires, under the subspecific name of notius, on the basis of 

 grayer dorsal coloration than is found in birds from Brazil. Hart- 

 ert^^ has considered this a synonym of spixi, but more lately Bra- 

 bourne and Chubb ^^ have cited it as a valid form. Examination of 

 the type-specimen shows it to be in very worn plumage, while a 

 second specimen from Conchitas is in similar condition. After 

 careful comparison of these two with six other skins of supposedly 

 typical spixi (Sapucay, Paraguay; Quinta, Rio Grande do Sul; 

 Santa Catherina, and two without locality) I can distinguish na 

 valid difference when due allowance is made for change in color 

 due to wear. 



The present bird was found only at Rio Negro, Uruguay, where 

 on February 19, 1921, 1 secured a male in immature plumage in low- 

 land thickets inhabited by S. a. frontalis. This bird has a mere trace 

 of rufous in the crown and less on the wings than in adults. It is 

 darker above and somewhat more brownish below than those in full 

 plumage. It is distinguished from S. a. frontalis in the same plum- 

 age by the absence of rufous in the tail. 



SYNALLAXIS FRONTALIS FRONTALIS Pelzein 



Synallaxis frontalis Pelzeln, Sitz, Akad. Wiss. Wien, Math.-Naturw. Kl.^ 

 vol. 34, 1859, p. 117. (City of Goyaz, Engenho do Cap Gama and 

 Cuyaba.) 



/Synallaxis a.zarae, while it has a wing measurement about equal to 

 frontalis, has a much longer tail ; Zimmer ^* considers frontalis spe- 

 cifically distinct from azarae, an opinion in which I concur. Hell- 

 mayr^^ considers Synallaxis frontalis of Pelzeln as based on the 

 female of Parulus ruftceps of Spix,^*^ and uses Spix's locality, Ria 

 Sao Francisco, as that of the type. Pelzeln, however, employs de- 

 scriptive terms with his name, although frontalis is given as a manu- 

 script name of Natterer, so that although he refers to Spix, the 

 name is based on description and must take as type locality the 



«2Nov. Zool., vol. 16, 1909, p. 211. 



« Birds of South America, 1912, p. 229. 



»* Field Mus. Nat. Hist., Zool. Ser., vol. 12, May 20, 1925, pp. 105-107. 



«5Nov. Zool., vol. 28, September, 1921, p. 264. 



««Av. Bras., vol. 1, 1824, p. 85, pi. 86, fig. 2. 



