YELLOW-NOSED MOLLYMAWK. 
There are also in the British Museum three eggs obtained on the visit of 
H.M.S. “ Challenger ” from the same colony. At the time the birds were 
not identified and Professor Moseley does not definitely describe them to any 
species. There is no doubt now in the light of later work that these three 
eggs are also those of T. chlorhynchus. 
Marked chiefly at the big end with spots of red-brown; in one case a cap 
of fine purplish specks. Measurements : 102.4 by 61.1 mm.; 95.7 by 60.1 ; 
97.2 by 58. 
Altogether I have examined eleven eggs of this species. Average size of 
eleven eggs, 97.4 by 61 mm. Maxima : 102.4 by 61.1 and 101.1 by 65.4. 
Minima : 92.4 by 62.9 and 97.2 by 58. 
Nest. Professor Moseley, in his book A Naturalist on the Challenger, has 
several notes on the colony of this species on Nightingale Island. 
He says : ‘ ‘ They make a cylindrical nest of tufts of grass, clay, and sedge 
which stands up from the ground. The nest is neat and round. There is a 
shallow concavity on the top for the bird to sit on, and the edge overhangs 
somewhat, the old bird undermining it, during incubation, by pecking away 
the turf of which it is made. 
“ I measured one nest, which was 14 inches in diameter and 10 inches 
in height.” 
He also says that the egg is held in a sort of pouch while the bird is incuba- 
ting. So that the bird has to be driven right off the nest before it will drop 
the egg out of its pouch, before one can see whether the egg has been laid or not. 
STERNA VITTATA Gm. 
(See ante, p. 81). 
Nest. Information as to the breeding of this species is very scanty. August 
von Pelzeln (Novara Expedition, Zoolog. Theil., Bd. I., p. 152) states that two 
females were shot in November at the Crater Bay of St. Paul’s Island. One 
of these was shot from a nest and apparently other nests were found. Most 
of them are described as being in the small holes of the steep basaltic cliffs 
along the coast and in the sides of the crater. According to Howard Saunders 
(Cat. Birds Brit. Mus., XXV., p. 52, 1896) this is confirmed by M. Velain, who 
describes this species as depositing its egg in the most inaccessible places in the 
crater at St. Paul’s Island. W. B. Alexander gives the breeding-range of 
S. v. vittata as including Ascension, St. Helena, St. Paul and Amsterdam Islands. 
Tristan da Cunha, Gough Island and Kerguelen. It certainly occurs on 
Kerguelen, but the only species recorded by R. Hall as breeding there is S, 
virgata. On Gough Island, birds in first plumage as well as an adult were obtained 
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