WHITE-CAPPED ALBATROSS. 53 
Genus DIOMEDELLA. 
Diomedella Mathews, Birds Austr., Vol. IT., pt. 3, p. 275, Sept. 20th, 1912. Type (by 
original designation): Diomedea cauta Gould. 
Larger Mollymawks with long bills, long wings, medium tails and stout legs 
and feet. 
The bill shows a space between the culminicorn and the latericorns posterior 
to the nostrils, and also between the culminicorn and the frontal feathers ; these 
spaces are diminished in extent in some of the forms but the culminicorn never 
broadens out, or conversely, narrows as in forms of Thalassarche. In the lower 
mandible the bar at the base shows an entry into the edge, not bounding it as in that 
genus. The wing is longer, but the tail is practically the same length. The feet 
are larger but of same nature. 
Coloration similar to that of T'halassarche. 
This genus approximates in some items to Diomedea. 
41. Diomedella cautaa—WHITE-CAPPED ALBATROSS. 
Gould, Vol. VII., pl. 40 (pt. xv.), June Ist, 1844. Mathews, Vol. II., pt. 3, pl. 100, Sept. 
20th, 1912. 
Diomedea cauta Gould, Proc. Zool. Soc. (Lond.), 1840, p. 177, July 1841: Bass Straits. 
Diomedella cauta rohui Mathews, Austral Av. Rec., Vol. III., pt. 3, p. 55, April 7th, 1916: 
Sydney, New South Wales. 
Diomedella cauta wallaca Mathews, ib., pt. 6, p. 160, June 25th, 1918. New name for 
preceding. 
DistriIsuTion.—Eastern and Southern Australian Seas. 
Adult male—Upper back slate-grey, with white bases and pale margins to the 
feathers ; scapulars ash-brown, white only at the extreme base ; wing-coverts 
dark brown with white bases ; the smaller coverts showing pale edges ; primary- 
coverts and primary-quills dark brown, the latter with white shafts and white on the 
inner webs ; secondaries also dark brown, with the basal portion of the inner webs 
white ; tail-feathers hoary-grey with white shafts ; a narrow eyebrow and a spot in 
front of the eye black, becoming pale towards the base of the bill, a patch behind the 
eye including the ear-coverts washed with plumbeous-grey ; head and neck all 
round white, as also the under-surface of body, including the axillaries, under wing- 
coverts white, the marginal ones blackish ; bill bluish horn, lower mandible darker, 
upper mandible with a narrow belt of black and on each side of the nostrils ; base 
of lower mandible with a belt of orange reaching to the corner of the gape ; iris 
brown ; feet bluish-white. Total length 987 mm. ; culmen 137, wing 590, tail 204, 
tarsus 86. 
Adult female—Similar to the adult male (? smaller) but with the grey on the 
sides of the neck paler, and the yellow markings on the bill duller. 
Immature.—Undescribed. 
Nestling —Covered with white down ; bill black. 
Nest—Composed of chocolate-coloured soil, largely mixed, when in a wet 
state, with rootlets and other vegetation, which gives it the appearance of peaty 
substance. It is smoothed over and holds together fairly well, varying in height 
externally from 3 to 7 inches. The measurements of an average nest are as follows : 
internal diameter 11} inches, external diameter 14, basal diameter 16}; external 
height 5}, internal depth 33. 
Egg—Clutch, one ; creamy-white, freckled more or less with reddish-brown 
surface-markings on the larger end. In some cases these markings were minute, 
numerous, and almost continuous, while in others they were much larger and darker, 
on a slightly reddish ground, but there were various gradations between the two 
