[264]

Ibis, 1880, pp. 340-349.

[265]

Dict. Birds, 1896, Introduction.

[266]

Untersuchungen zur Morphologie und Systematik der Vögel, Amsterdam, 1888.

[267]

Bronn's Thier-Reich, Aves. Syst. Theil, 1893, pp. 270-273.

[268]

Cat. Birds Brit. Mus. xiv. 1888.