of certain Birds in North-eastern Africa. 129 



large size and of a pale violet-grey or browuish-grey colour, with 

 some light-brown points besides; or the markings more di- 

 stinct and numerous, grey and reddish-brown, sometimes shining 

 dark-brown with lighter edges, or reddish-grey and reddish- 

 brown, densely dotted on the obtuse end. As in most of the 

 Laridce, the spots are rounded and laterally produced. The shell, 

 held against a light, is transparent yellow ; its weight is about 

 35 grains. Their granulation is flat, somewhat resembling that 

 of Rhynchops. 



8. Larus hemprichii, Bp. 



This bird breeds on theAmarat Islands, at a greater distance 

 from the shore than Sterna senegalensis, in companies of six to 

 ten pairs. Such a small colony was found by Heuglin on a 

 plain of sand surrounding a hill and covered with salt-plants 

 and bushes. The greater part of the young ones were hatched 

 on the 27th of July, 1857. Three nests only, two with two 

 eggs, and the third with one, all hard-set, remained. They lay 

 in the sand beneath some bushes. The eggs, which are from 23 

 to 24| lines long and 16 to 17| lines broad, equal in size those 

 of Larus tridactylus, the smallest eggs of Larus canus, and the 

 largest ones of Larus ridibundus. The pale greyish-yellow, rarely 

 brownish-yellow, sometimes greenish-grey ground-colour is 

 speckled, dotted, and striolated with grey and pale-brown. They 

 are moderately shining, and have a weight of 46 to 48 grains or 

 more. The granulation is somewhat stronger than in Larus 

 ridibundus, but not so strong as in Larus canus, and less uniform 

 than in Larus tridactus. 



The old birds endeavoured to lead away the attention of visi- 

 tors from their offspring. The young birds have whitish down ; 

 they are hidden in the thick thorn-bushes immediately after their 

 being hatched, and afterwards, before they are able to fly, brought 

 into shallow water. 



9. Larus leucophthalmus, Licht. 



When Heuglin examined the island of Perim (which has 

 lately become of so great political importance), he found a high 

 rocky part of it almost exclusively occupied by Larus leuc- 

 ophthalmus, which had selected that spot for breeding (17th 



