_Amazona xantholora_ (Gray): Yellow-lored Parrot.--The species was abundant in the vicinity of Champotón. Large flocks congregated near camp; the birds began to assemble about an hour before dark. One was shot from a flock that flew over our camp and another was taken at night from its roost in a small tree about 10 feet above a trail. One small flock of _Amazona_ was seen 4 km. NNE Felipe Carrillo Puerto. All specimens were molting. Specimens (3): [Male], 40483, testis 5 × 2 mm., 229.1 gm., molting--extensive body molt, 6th primaries ensheathed (July 9), and [Female], 40484, ovary 13 × 9 mm. (inactive), 209.0 gm., molting--extensive body molt, wing molt complete (July 11), 5 km. S Champotón; [Male], 40485, testis 5 × 2 mm., 210.9 gm., molting--extensive body molt, 7th primaries ensheathed (August 16), 4 km. NNE Felipe Carrillo Puerto. _Amazona albifrons nana_ Miller: White-fronted Parrot.--This species was common west of Escárcega where large flocks were seen every evening. A specimen of _A. albifrons_ was taken south of Champotón where this species occurred in large flocks with _A. xantholora_. One specimen was taken from a small flock near Chichén-Itzá. Specimens (5): [Male], 40487, testis 8 × 4 mm., 210.0 gm. (July 10), 5 km. S. Champotón; [Female], 40488, ovary inactive, 205.5 gm., molting (July 12), [Male], 40489, 232.5 gm., molting (July 13), and [Female], 40490, ovary inactive, 206.1 gm. (July 14), 7-1/2 km. W Escárcega; [Female], 40486, ovary inactive, 176.0 gm. (July 27), 2 km. E Chichén-Itzá. _Coccyzus americanus americanus_ (Linnaeus): Yellow-billed Cuckoo.--A female taken at Pisté substantiates Paynter's (1955a) suggestion that the species breeds on the peninsula. Specimen (1): [Female], 40491, ovary 12 × 9 mm., 58.7 gm., well-developed brood patch (July 22), Pisté. _Coccyzus minor_ (Gmelin): Mangrove Cuckoo.--In view of the paucity of recent records of this species from the mainland of the peninsula, it is noteworthy that several individuals were seen flying to and from the beach and mangroves late one evening about 4 km. W Sisal. _Piaya cayana thermophila_ Sclater: Squirrel Cuckoo.--This species was seen at our camps near Champotón, Pisté, Pueblo Nuevo X-can, and Puerto Juarez. The slightly enlarged (probably regressing) testes of males examined seem to be the only evidence of breeding activity in the species on the peninsula. Specimens (3): [Male], 40493, testis 8 × 6 mm., 99.6 gm. (July 14), and [Female], 40494, 90.0 gm. (July 14), 7-1/2 km. W Escárcega; [Male], 40492, testis 5 × 2 mm., 97.5 gm., molting (August 14), 4 km. NNE Felipe Carrillo Puerto. _Crotophaga sulcirostris sulcirostris_ Swainson: Grove-billed Ani.--Three half-grown juveniles were taken at Pisté and a pair in breeding condition was taken at Pueblo Nuevo X-can. These seem to be the first breeding records from the peninsula.