Specimens (3): [Male], 40628, 33.5 gm. (July 10), 5 km. S Champotón; [Female], 40626, ovary 6 × 3 mm., brood patch, 34.0 gm. (July 20), [Female], 40627, ovary inactive, 33.9 gm. (July 26); 3-1/2 km. N and 6-1/2 km. W Pisté. _Tityra semifasciata personata_ Jardine and Selby: Masked Tityra.-- Previously, breeding information for this species has been available only for March (Paynter, 1955a:184). Adults were observed feeding young fledglings 7-1/2 km. W Escárcega on July 15, and a juvenile was taken. Gonads of males were in full breeding condition. Specimens (5): [Male], 40630, testis 13 × 6 mm., 81.3 gm. (July 14), sex? 40631, juv., 55.5 gm. (July 15), [Male], 40632, testis 9 × 5 mm., 73 gm., molting--1st and 2nd primaries ensheathed (July 15), and [Female], 40633, 84.7 gm. (July 16), 7-1/2 km. W Escárcega; [Female], 40629, ova to 1 mm., 80.0 gm. (July 23), Pisté. _Erator inquisitor fraserii_ (Kaup): Black-capped Tityra.--Breeding has been recorded by Paynter (1955a:185) on April 26. A moderately enlarged testis (probably regressing) was noted in the specimen from Pisté, on July 21. Specimens (2): [Female], 40635, 51.8 gm. (July 15), 7-1/2 km. W Escárcega; [Male], 40634, testis 6 mm., 51 gm., molting--6th primaries ensheathed (July 21), Pisté. _Pipra mentalis mentalis_ Sclater: Red-capped Manakin.--The specimens here reported seem to be the first from the peninsula in which reproductive activity has been recorded. Specimens (2): [Male], 40637, testis 5 × 3 mm., 14.0 gm. (July 29), Pueblo Nuevo X-can; [Male], 40636, testis 5 × 2 mm., 14.6 gm. (August 3), 4 km. WSW Puerto Juarez. _Pyrocephalus rubinus_ (Boddaert): Vermillion Flycatcher.--This species was seen only in the arid scrub 2-13 km. WSW of Sisal. Breeding seemingly had ended by early August, as evidenced by four adults that showed no gonadal activity and were in advanced stages of molt. Specimens (5): [Female], 40638, juv., 12.1 gm. (August 7), 1-1/2 mi. S Sisal; [Female], 40640, ovary inactive, 14.1 gm., molting--6th primaries ensheathed (August 10), [Female], 40641, ovary inactive, 13.9 gm., molting--7th primaries ensheathed (August 10), and [Male], 40642, testis 2 mm., 14.6 gm., molting--5th primaries ensheathed (August 10), 13 km. WSW Sisal; [Female], 40639, testis 1 mm., 14.0 gm., molting--7th primaries ensheathed (August 18), 2 km. SW Sisal. _Tyrannus melancholicus chloronotus_ Berlepsch: Tropical Kingbird.--Most specimens were molting. A male and two females from Pisté taken on July 21 and a female from Pueblo Nuevo X-can (July 29) had slightly enlarged (probably regressing) gonads. Three immatures were collected and adults were seen feeding young fledglings at Pisté. There seems to be no other breeding records from the peninsula.