624 Bulletin American Museum of Natural History. [Vol. XXXVI, 



(4444) Gymnostinops yuracares (d'Orb. & Lafr.). 



Cassicus yuracares d'Orb. & Lafr., Syn. Av., II, p. 2; Mag. de Zool., 1838, p. 2 

 (Yuracaris, Bolivia). 



Gymnostinops yuracares caurensis Todd, Proc. Biol. See. Wash., XXVI, 1913, 

 p. 170 (R. Caura, Venez.). 



Occurs in Colombia only in Amazonia. Mr Todd has kindly loaned me 

 a type and topotype of his Gymnostinops yuracares caurensis and I find that 

 they can be closely matched by specimens in our collection from Bolivia and 

 western Matto Grosso. There appears to be much variation in this species 

 in the color of the anterior parts of the body, some birds having it analine- 

 yellow, others yellowish olive. In two of the Colombian specimens listed 

 below it is analine-yellow, in a third immature female it is much darker. 

 Two adult males from Napo and a 'Bogota' skin are analine-yellow. Two 

 males and a female from Jutumpampa, Bolivia, agree with one another and 

 all have the parts in question analine-yellow; but in a male from the lower 

 Beni, Bolivia, and two males from Campo Novo, Matto Grosso, they are 

 dark yellowish olive. 



Of the two specimens of "caurensis" the type has the anterior areas 

 slightly lighter than in the Beni specimen above-mentioned, while the second 

 Caura specimen resembles the two specimens from Matto Grosso. In one 

 the bill agrees in size with that of Bolivian and Brazilian specimens, in the 

 other it is shghtly smaller with the culmen somewhat narrower basally, but 

 the difference is slight and does not impress me as being of diagnostic value. 

 I conclude therefore that the characters attributed to caurensis (" darker . . . 

 bill decidedly weaker") are individual rather than racial. 



Florencia, 1; La Morelia, 1. 



(4445) Ostinops decumanus {Pall.). 



Xanthornus decumanus Pall., Spic. Zool.; Fasc. VI, 1769, p. 1 (Surinam). 



Ostinops cristatus Cass., Proc. Acad. N. S. Phila., 1860, p. 138 (Turbo; R. Atrato) ; 

 Wyatt, Ibis, 1871, p. 328 (lower mountain districts, Bucaramanga region). 



Ostinops decumnnus Sol. & Salv., P. Z. S., 1879, p. 508 (Remedios); Robinson, 

 Flying Trip, 1895, p. 160 (R. Magdalena); Stone, Proc. Acad. N. S. Phila., 1899, 

 p. 307 (R. GuaU; R. Combeima); Allen, BuU. A. M. N. H., XIII, 1900, p. 163 

 (Onaca). 



One of the most conspicuous and characteristic birds of the Tropical 

 Zone. It is found in the Cauca and Magdalena Valleys and Amazonian 

 region but appears to be absent from the Pacific Coast region. 



Although like other species of the genus it is an inhabitant of forests. 



