Novitates Zoolooicae XXXVI. 1930. 27 III. LIST OF THE BIRDS COLLECTED BY ERNST MAYR. By ERNST HARTERT. 1. Gymnocorvus tristis (Less. & Garnot). This common bird which is spread over New Guinea, where it is also common on the Hydrographer Mountains, was found in various stages of coloration in Arfak on the hills near Siwi, 7 . v . 1 928, at Wondiwoi (Wandammen) 1900 m. high, at Hollandia and Ifaar on Lake Sentani (south of Hollandia). The Iris is marked light blue (juv.) and brown (med.). In the stomach fruits. (According to the researches of Sherborn the above name was published first. For a long time this Raven was known as Gymnocorvus senex.) 2. Ailuroedus melanotis arJakianus Meyer. Ailuroedus arfakiatius A. B. Meyer, Silzungsber. Akad. Wiss. Wien, xlix, p. 82 (Arfak Mts.). This form was found to be not rare at Siwi (Arfak) and Ditchi (1200 m.). " Iris braun, hellbraun, dunkelbraun. Schnabel weissgrau, hellhornfarben. Fiisse grau." Of great interest are two young birds from Siwi, shot 19. iv. and 15. v. 1928. They have thick brownish white downy plumage on the underside in which a feather of the adult is just appearing. The head is thickly covered with rufous-brown down, the underside with a mesoptile of soft down-like plumage of a brownish-grey, darker basally, sides of body browner. Interscapulium and wings already green as feathers in adult. " Iris grau, Schnabel hell, Fiisse bleigrau." Wings of sexed males 163, 167, 160 — others moulting. A female is evidently shorter in the wing, but the latter is too much worn to give a measure-ment. In 1895 Lord Rothschild described, from a specimen bought from Renesse van Duivenbode a skin without a label, but said to be from Jobi, as "Ailuroedus jobiensis." Later on he considered this name to be a synonym, and I concurred in this opinion. I am, however, now convinced that it is not a synonym. Besides the type we have now three other specimens of various native preparations which differ from the eight adult skins sent by Dr. Ernst Mayr, in having the spots on the head not pure white or very nearly white but brown, and much larger, and quite brown (instead of whitish) centres to the feathers of the hind-neck and upper interscapulium ; moreover, in the type of jobiensis and one of our other specimens the black of the throat reaches further down to the breast. These specimens have no indication of locality, but I now consider it possible, that they are from another locality, though perhaps not from Jobi. These birds approach Stresemann's guttaticollis from the Hunsteinspitze, Sepik Region.