It is again possible that the _Bucco_ of Tucuman may be the Paraguayan _B. chacuru_ of Vieillot, founded upon the "_Chacuru_" of Azara, which is another species not remotely allied to _B. maculatus_. Fam. XXVII. CUCULIDÆ, or CUCKOOS. The Cuckoos form an extensive and rather varied family of zygodactyle birds with a somewhat wide distribution, being found in all parts of the world except in the extreme north, where their insect-food would not be abundantly met with. The true _Cuculi_, so remarkable for their parasitic habits, are not found in the New World, but several genera of arboreal Cuckoos (_Coccyzus_, _Piaya_, &c.), and others of terrestrial habits (_Crotophaga_, _Geococcyx_, and _Saurothera_), are met with, chiefly in the Neotropical Region, and number altogether some thirty species. Of these, eight are known to occur within the confines of the Argentine Republic. 267. CROTOPHAGA ANI, Linn. (BLACK ANI.) +Crotophaga ani+, _Scl. et Salv. Nomencl._ p. 107; _White, P. Z. S._ 1882, p. 619 (Salta). _Description._--Black, glossed with bronzy and purplish; bill and feet black; bill with the culmen much elevated, compressed and cultrate: whole length 13·0 inches, wing 5·5, tail 7·0. _Female_ similar. _Hab._ Veragua and South America down to Northern Argentina. This strange Cuckoo, with the plumage and some of the habits of a Crow, is of a nearly uniform black, glossed with bronze, dark green, and purple. Its most peculiar feature is the beak, which is greater in depth than in length, and resembles an immense Roman nose, occupying the whole face, and with the bridge bulging up above the top of the head. The Ani is found only in the northern portion of the Argentine territory. According to Azara it is very common in Paraguay, and goes in flocks, associating with the Guira Cuckoo, which it resembles in its manner of flight, in being gregarious, in feeding on the ground, and in coming a great deal about houses; in all which things these two species differ widely from most Cuckoos. He also says that it has a loud disagreeable voice, follows the cattle about in the pastures like the Cow-bird, and builds a large nest of sticks lined with leaves, in which as many as twenty or thirty eggs are frequently deposited, several females laying together in one nest. His account of these strange and disorderly breeding-habits has been confirmed by independent observers in other parts of the continent. The eggs are oval and outwardly white, being covered with a soft white cretaceous deposit; but this can be easily scraped off, and under it is found a smooth hard shell of a clear beautiful blue colour. 268. GUIRA PIRIRIGUA (Vieill.). (GUIRA CUCKOO.)