STERXA MACKURA. 295 



They were very numerous at the mouth of the river at Larache 

 during April. 



The Sandwich Tern is very common in the Straits in autumn, 

 winter, and spring. Sometimes thirty or forty may be noticed 

 sitting together on the small isolated rocks near Cabrita Point, 

 and will allow a boat to approach within a few yards. They pass 

 north about the first week in April, when I killed an old male 

 tinted on the breast and under wing-coverts with a beautiful 

 pink blush, just as is sometimes found in the spring on old males 

 of the Brown-headed Gull (Lanes ridilundus). They nest in 

 the marisma and, according to Arevalo, near Malaga. 



Head black ; tail white ; bill black, with yellow tip ; legs black. Length 

 15 inches. 



333. Sterna media, Horsfield. The Allied Tern. 



" This species is one of the least common of the Terns near 

 Tangier, and only occasionally met with. Further south, in the 

 vicinity of Larache, it is more frequently seen ; and I found it 

 there during September, October, and November, in company 

 with S. cantiaca, which species it resembles in habits." Favier. 



This Tern occurs in the Straits in spring. Two, both males, 

 were shot near Tarifa on the 20th of April, 1873, and many have 

 been obtained near Tangier. Probably they breed on the coast. 



This bird is very much like the Sandwich Tern (S. cantiaca), but is a 

 trifle larger and has the bill yellow. I found, on comparing male specimens 

 shot on the same day, that it differs from that species also in having the bill 

 stouter in proportion, and the lower mandible slightly angulated, or " Gull- 

 billed." The feathers of the black crest are more elongated, and the upper 

 tail-coverts and tail are grey, the same colour as the back. The primaries 

 underneath are more broadly marked with grey next the shafts ; and the 

 tarsus is rather longer. 



334. Sterna macrura, Naumaun. The Arctic Tern. 



I obtained this Tern in winter plumage in the Straits of 

 Gibraltar; and there is no doubt that they occur regularly on 



