DIGLOSSA. 241 



Section III. OSCINES TENUIKOSTRES. 



Fam. CCEEEBID^. 



DIGLOSSA. 



Diglossa, Wagler, Isis, 1833, p. 280 (type D. baritula) ; Hartl. Rev. Zool. 1842, p. 56 ; Sclater, 



Ibis, 1875, p. 206. 

 Agrilorhinus, Bp. Nouv. Ann. Sc. Nat. i. p. 408 (1838). 



The members of this peculiar genus are almost confined to the Andes of South 

 America from Bolivia in the south to Colombia and Venezuela in the north. One 

 species is found in the highlands of Guiana and two within our region — D. plumbea 

 being peculiar to the highlands of Panama and Costa Rica, and B. baritula having 

 a wider range in Southern Mexico and Guatemala. All the members of the genus are 

 found in upland, forests, never probably descending below an elevation of 6000 feet. 



Mr. Sclater has recently published a monograph of the genus Diglossa, in which he 

 includes fifteen species. To these we have added a sixteenth, B. glauca of Bolivia. 

 The species in this monograph are divided into two sections, according as their plumage 

 is mingled with rufous or whole-coloured. All, however, are very closely allied, and 

 all have the peculiar formation of the bill which makes the genus one of easy recog- 

 nition. 



Diglossa baritula was the first species discovered, and became the type of the 

 genus Diglossa, described by Wagler in 1832. The same species furnished the type 

 specimens of Prince Bonaparte's genus Agrilorhinus, and also of Lichtenstein's Cam- 

 pylops, which latter name, according to Dr. Cabanis, was not published till 1851, when 

 it was mentioned in the first part of the ' Museum Heineanum.' The whole genus was 

 split up by Cassin in 1864 into a number of smaller subgenera, the characters of which 

 were drawn from coloration. Mr. Sclater justly remarks that this step was not at all 

 necessary. 



Diglossa may easily be recognized from all the rest of the Coerebidse by the hook of 

 the maxilla, which projects a long way beyond the end of the mandible, and is abruptly 

 curved downwards ; the mandible is rather swollen at the base, and curves upwards 

 towards the end. On the cutting-edge of the maxilla, just before the commencement 

 of the curve of the terminal hook are several dentate serrations. The nostril is over- 

 hung with a membrane ; the rictal bristles are well developed. The tongue is divided 

 towards the end (hence the origin of the name of the genus). The wings are moderately 

 rounded, the first primary well developed, about equal to the seventh, the third and 

 fourth equal and longest. The tail is moderately forked. 



BIOL. CENTE.-AMER., Aves, Vol. I., November 1883. 31 



