202 BROOKLYN IXSTITUTE MUSEUM. SCIENCE BULLETIN 2. 6. 
but several of the species are more abundant at some seasons than at 
others. Or, it is not impossible that the relative abundance or paucity 
of a given species at any particular season is more apparent than real 
and is dependent on the habit certain forms have of congregating into 
great flocks during the dry season. As a group, birds of this family 
are well known and characteristic of the region. The long purse-like 
nests of colonies of some of the hang-nests are conspicuous objects in 
many a landscape. The brilliant plumages of others attract attention, 
while the vocal powers of certain species are unrivaled among tropical 
birds. 
Key to the Genera. Species and Subspecies of Icteridae. 
a. Outstretched feet reaching beyond the end of the tail and claw of hind 
toe elongated. 
6. Outer tail-feathers largely or entirely white Sturnella jnaf^na tneridiona- 
lis. 
b'. Outer tail-feathers not white. 
c. More or less red in plumage of under parts (adult males with throat 
and breast bright scarlet) Leistes miiitaris. 
c\ No red in plumage of under parts Dolichonyx oryzivorus. 
a'. Outstretched feet falling short of end of the tail and claw of hind toe not 
elongated, 
b. Black with iridescent lustre (male) or brown (female). ' 
c. Frontal plumes erect Lainpropsar lattagrinns 
guianensis. 
c'. Frontal plumes not erect. 
d. Size large, wing more than 150 mm. Neck feathers lengthened 
and expanded "• Cassidix oryzivora oryzivjra. 
d'. Smaller, wing less than 150 mm. 
e. Length of bill not more than twice its depth; tail square or but 
slightly rounded. 
/. Size large wing more than 120 mm Molothrus cabanisi. ^ 
f. Smaller, wing not more than 120 mm. 
g. Wing not over 105 mm Molothrus atroniteTts. * 
g'. Wing more than 105 mm Molothrus bonariensis 
venezuelensis. 
e'. Length of bill more than twice its depth. Tail much rounded. 
almost wedge-shaped Holoqtuscalus lugubris. 
b'. Not uniformly black or brown, above and below. 
c. Throat uniform with breast and sides and general color of under parts 
olive green, black or brown. 
d. Entire under parts uniform (black); above, rump bright red Cacicus haemorrhoiis. 
d'. Under tail-coverts not uniform with breast. 
e. Rump yellow Cacicus cela. 
e'. Rump chestnut. 
/. Body black Ostinops dfcumanus. 
/'. Body olive green Ostinops viridis. 
'The females of Lampropsar tanagrinus resemble the males and are black and slightly glossy. 
^^Neck feathers not expanded in females. 
Hn the British Museum Catalogue of Birds, XL 1886. 338. this species is recorded from Caracas, 
Venezuela, and Trinidad, so it is not improbable that it will be found later in the delta region of the Orinoco. 
*Hellmayr. Novit. Zool. XIIL 1906. 20. designates the Coast of British Guiana as the type locality. 
The species is found in Trinidad, and Venezuela is included in the habitat given in the Catalogue of Birds, 
British Museum XL 1886. 337. so we may confidenUy expect it in the delta region of the Orinoco. 
