Cyclarhis gujanensis insularis Ridgway: Rufous-browed Pepper-shrike.—Specimen (1): ♂, 40794, testis 2 mm., 37.8 gm., molting—4th primaries ensheathed (August 9), 4 km. N San Miguel, Isla Cozumel.
Vireo bairdii (Ridgway): Cozumel Vireo.—Specimens (4): ♀, 40795, ovary inactive, 12.7 (August 8), ♂, 40796, testis 2 mm., 12.6 gm., molting—3rd and 4th primaries ensheathed (August 10), ♀, 40797, ovary inactive, 12.5 gm., molting—3rd primaries ensheathed (August 10), and ♂, 47098, imm., 13.1 gm. (August 10), from 2½-3½ km. N San Miguel, Isla Cozumel.
Vireo pallens semiflavus (Salvin): Mangrove Vireo.—Paynter (1955a:236) noted breeding by this species from April 7 through June.
Specimens (2): ♀, 40800, ova to 3 mm., oviduct enlarged (July 8), Isla del Carmen; ♀, 40799, ovary inactive, 11.1 gm., molting—4th primaries ensheathed (August 2), Isla Mujeres.
Vireo flavoviridus flavoviridus (Cassin): Yellow-green Vireo.—Paynter's (1955a:238) data indicate breeding in this species from late May through June; our records indicate that the species breeds at least through July.
Specimens (12): ♂, 40812, testis 10 × 4 mm., 17.1 gm., molting—1st, 2nd, and 3rd primaries ensheathed (July 17), and ♂, 40813, testis 7 × 4 mm., 18.2 gm. (July 17), 1 km. N, 13 km. W Escárcega; ♀, 40803, ovary 9 × 5 mm., ova to 1 mm., brood patch (July 21), ♂, 40805, testis 11 × 6 mm., 18.5 gm. (July 21), ♂, 40804, 18 gm. (July 21), and ♀, 40802, ovary slightly enlarged, molting—2nd and 3rd primaries ensheathed (July 21), all from Pisté; ♂, 40806, 17.5 gm., molting—1st primaries ensheathed (July 21), 6½ km. W Pisté; ♀, 40808, ovary 5 × 3 mm., 17.4 gm. (July 28), ♂, 40807, testis 5 × 3 mm., 17.7 gm., molting—3rd and 4th primaries ensheathed (July 28), ♂, 40809, testis 2 × 1 mm., 17.5 gm. (July 29), and ♂, 40810, testis 3 × 2 mm., 18.7 gm., molting—1st, 2nd, 3rd, and 4th primaries ensheathed (July 30), from Pueblo Nuevo X-can; ♂, 40811, testis 3 × 1 mm., 18.7 gm., molting—4th, 5th, and 6th primaries and middle pair of rectrices ensheathed (August 14), 4 km. NNE Felipe Carrillo Puerto. Mallophaga: Philopterus sp. July 21.
Vireo magister (Lawrence): Yucatán Vireo.—Breeding on the peninsula has not been recorded previously. A male, beginning to molt, taken on August 10 on Isla Cozumel had enlarged testes, which were apparently regressing.
Specimens (3): ♀, 40814, ovary inactive, 17.7 gm. (August 2), Isla Mujeres; sex? 40815, 19.5 gm. (August 9), and ♂, 40816, testis 6 × 3 mm., 20.2 gm., molting—1st, 2nd, and 3rd primaries ensheathed (August 10), 3½ km. N San Miguel, Isla Cozumel.
Cyanerpes cyaneus carneipes (Sclater): Blue Honeycreeper.—Paynter (1955a:283) collected specimens that were breeding in April. Testes were fully enlarged in two August-taken specimens and courtship rituals were observed in two pairs seen on August 3 at Puerto Juarez.
Specimens (3): ♂, 40817, 15.5 gm. (July 21), 6½ km. W Pisté; ♂, 40818, testis 12 × 6 mm., 12.1 gm. (August 3), 4 km. WSW Puerto Juarez; ♂, 40819, testis 8 × 6 mm., 11.6 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.