J914J Crandall: Notes on Costa Rican Birds. 339 



On May 5th, while inspecting the nests of a colony of Gym- 

 7iostinops montezuma, a recently hatched bird was found in 

 company with a young Gymnostmops. This nestling's skin was 

 white, with occipital, humeral, dorsal and lateral tracts, as 

 well as a slight scattering on the thighs, well covered with 

 long, dark gray down. The beak was white and the gape wide 

 and yellowish. It was in striking contrast with its blackish, 

 downless nesT;-mate and was no doubt a young Cassidix. Its 

 behavior was quite in contrast to that of Gymnostiyiops, which 

 shrunk to the bottom of the nest when disturbed, while the 

 young interloper gaped eagerly for food. The two birds were 

 of approximately the same size and equally well nourished. They 

 could not have been more than two or three days old. 



In a second nest was found an egg of Gymnostinops ac- 

 companied by another (Fig. 116) of quite different appearance. 

 This egg is spotless white, rough in texture and slightly glossed. 

 It measures 36.1 mm x 26.0 mm, which approximates the dimen- 

 sions of two eggs of Cassidix oryzivora oryzivora in the collec- 

 tion of the British Museum,^ and substantiates the belief that 

 the present specimen is referable to C. oryzivora mexicana. It is 

 of interest to note that the egg of Gymnostinops m,ontezuma 

 was addled and evidently deserted, while its fellow was quite 

 fresh. 



It is remarkable that with three separate evidences of the 

 presence of Cassidix, not one adult bird was observed, although 

 much time was spent in observation of colonies of both Gym- 

 nostinops and Zarhynchus. Carriker^ records that in several 

 years of collecting in Costa Rica, he saw but a single specimen 

 of Cassidix, and this one at Guapiles. This bird was referred 

 to C. oryzivora mexicana. 



Gymnostinops montezuma (Less.). Montezuma Giant 



Cacique. 



This Oropendula apparently is the most abundant Icterine 

 bird of the Caribbean lowlands. Its colonies are of frequent oc- 

 currence and the birds, often in company with Psilorhinus. 

 mexicanus cyanogenys, are almost ubiquitous. They were 



1 Catalogue of the Collection of Bg-gs in the British Museum. Vol. V, 

 p. 372. 



2 Birds of Coata Rica. etc. v>.. 832. 



