Dendrocincla homochroa homochroa (Sclater): Ruddy Woodhewer.—May 20 seems to be the only previous date of record for breeding in this species (Paynter, 1955a:171); our specimen extends the known season nearly three months.
Specimen (1): ♀, 40616, ovary 13 × 6 mm. (ova to 2 mm.), brood patch, 35.1 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Sittasomus griseicapillus (Vieillot): Olivaceous Woodcreeper.—Specimens (2): ♂, 40617, juv., 11.2 gm. (July 26), Pisté; ♀, 40618, ovary inactive, 10.5 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto.
Xiphorhynchus flavigaster (Swainson): Ivory-billed Woodcreeper.—According to Paynter (1955a:173), indications of breeding have been observed in specimens of this species taken between March 27 and June 5. A male taken on August 15 had moderately enlarged (probably regressing) testes and was well into the molt.
Specimen (1): ♂, 40619, testis 5 × 3 mm., 51.5 gm., molting—5th primaries and middle pair of rectrices ensheathed (August 15), 4 km. NNE Felipe Carrillo Puerto.
Lepidocolaptes souleyetii (Des Murs): Streak-headed Woodhewer.—This appears to be the second specimen recorded from the peninsula (see Traylor, 1941).
Specimen (1): ♂, 40621, testis 3 × 1 mm., 26.6 gm., molting—6th primaries ensheathed, middle pair of rectrices are new (July 17), 1 km. N, 13 km. W Escárcega.
Synallaxis erythrothorax Sclater: Rufous-breasted Spinetail.—Specimen (1): ♂, 40622, imm. skull, 16.1 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Thamnophilus doliatus (Linnaeus): Barred Antshrike.—Specimen (1): ♀, 40623, ovary 8 × 5 mm. (inactive), 26 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.
Formicarius analis (d'Orbigny and Lafresnaye): Black-chinned Antthrush.—Specimen (1): ♂, 40624, 56.0 gm. (July 29), Pueblo Nuevo X-can.