220 PODICIPID^. 
cnstatas, being seldom observed on passage. Some remain 
in the country to breed, the others migrating northwards in 
March, returning again during September. They are more 
abundant at the lakes of Ras-Dowra, and are there called 
Mazan by the Arabs.^' — Favier. 
I have seen specimens of the Red-necked Grebe obtaiined 
in Morocco by Favier so young that they must have been 
bred in the country ; and although I was unable to procure 
a specimen for identification, I am confident I saw several 
of this species at Ras-Dowra in April. I have no record of 
its occurrence on the Spanish side. 
The adult bird, in breeding-plumage, has no crested frill ; 
but the neck in front is of a chestnut-red colour; this part 
in winter is grey. 
Entire length about 16'5 inches. 
333. PoDicEPS AURiTus, Liun. The Sclavonian Grebe. 
Although Favier has not mentioned this Grebe as occurring 
near Tangier, I have seen one specimen obtained in the 
Straits in October 1867 ; and probably it is often to be met 
with in winter. 
Slightly larger than the next species {Podiceps nigricollis) , 
it is always to be distinguished, either in winter or immature 
plumage, by the bill, which is straight, forming an elongated 
cone, as in the two previous species. In the summer plumage 
it is frilled and crested^ and may be termed a miniature Great 
Crested Grebe. 
Total length about 13 inches. 
334. Podiceps nigricollis, Sundev. The Eared Grebe. 
This species is the most common of the Grebes, breeding 
in lagoons and swamps on both sides of the Straits. In the 
winter they take to the salt water, and are generally plentiful 
in Gibraltar Bay. 
The Eared Grebe is always to be distinguished by the bill, 
which turns slightly up, particularly the lower mandible. 
In breeding-plumage the adults have a red chestnut patch 
