Specimens (5): [Male], 40535, testis 3 mm., 2.9 gm. (July 12), and [Male], 40536, testis 2 mm., 3.6 gm. (July 14), 7-1/2 km. W Escárcega; [Male], 40531, testis 2 mm., 4.3 gm. (July 28), [Male], 40532, 3.8 gm. (July 28), and [Female], 40533, ovary inactive, 3.9 gm. (July 29), Pueblo Nuevo X-can. _Amazilia rutila_ (DeLattre): Cinnamomeous Hummingbird.--In addition to the two localities from which specimens were taken, several individuals were seen near the airstrip at Puerto Juarez. Specimens (2): [Female], 40538, ovary inactive, 4.1 gm. (July 30), 1-1/2 km. S, 1 km. E Pueblo Nuevo X-can; [Male], 40539, testis 2 mm. (August 14), 4 km. NNE Felipe Carrillo Puerto. _Amazilia yucatanensis_ (Cabot): Yucatán Hummingbird.--Many of these hummingbirds were seen among the coco palms on Isla del Carmen. A female taken on August 14 with a moderately enlarged ovary may indicate that the breeding season extends well into the summer. Specimens (4): [Male], 40540, testis 2 mm., 4.7 gm. (July 7), [Female], 40541, ovary inactive, 3.0 gm. (July 8), and [Male], 40543, 3.0 gm. (July 8); 1 km. SW Puerto Real, Isla del Carmen; [Female], 40542, ovary 6 × 2 mm. (ova to 1 mm.), 2.9 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto. _Trogon citreolus melanocephala_ Gould: Citreoline Trogon.--This species was heard or seen at all localities where deciduous forest was present. Specimens (7): [Female], 40557, ovary 14 × 8 mm. (ova to 2 mm.), brood patch, 72.5 gm. (July 16), and [Male], 40558, 66.5 gm. (July 16), 7-1/2 km. W Escárcega; [Male], 40553, 74.0 gm. (August 1), [Female], 40552, 74 gm. (August 1), [Female], 40554, ova to 3 mm. (August 2), and [Male], 40555, 76.2 gm. (August 2), 4 km. WSW Puerto Juarez; [Female], 40556, 76.4 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto. _Chloroceryle americana septentrionalis_ (Sharpe): Green Kingfisher.--My only specimen is a male (40559) shot near a large aguada at Rancho San Miguel, 4 km. NNE Felipe Carrillo Puerto on August 16. The specimen weighed 40.5 gm. _Ceryle torquata_ (Linnaeus): Ringed Kingfisher.--Paynter (1955a:154) noted that this "species has not been recorded from Yucatán but it is undoubtedly present, at least in the sheltered lagoon behind the barrier bar." A single individual was seen in one of these lagoons on August 9 and 10.