288 



LONG-WINGED SWIMMERS — LONGIPENNES. 



anteriorly in a point near the end of the feather. Rest of the plumage, including nape, pure white, 

 the lower parts tinged with delicate rose-pink in fresh specimens. Bill red (yellowish or orange in 

 dried skills) ; iris brown ; legs and feet black. Adult, in winter: Similar, but forehead and lores 

 white ; crown white, spotted with dusky ; occipital crest and side of head to in front of the eyes, 

 deep black. Young (first plumage) : Pileum dull brownish black, nearly uniform on the occiput, 

 where the feathers are not elongated, but short and blended ; whole crown streaked with white ; fore- 

 head and lores white, finely 

 streaked with black. Nape, 

 upper tail-coverts, and lower 

 parts, white, the lower part cf 

 the first with sparse roundish 

 spots ; back, scapulars, and wing- 

 coverts dirty whitish, coarsely 

 and irregularly spotted with 

 dusky brown, this color almost 

 uniform near the anterior portion 

 of the lesser wing-covert region, 

 the anterior border of which is 

 white ; secondaries dusky, bor- 

 dered terminally with white ; 

 primaries hoary slate, with a 

 narrow terminal border of white, 

 the inner webs mostly white, 

 with a broad dusky stripe next the shaft. Tail-feathers brownish slate, becoming grayish 

 basallv, the ends conspicuously bordered with white. Bill reddish ; feet dusky. 



Wing, 12.40-12.50 inches; tail, 6.60-7.30, the depth of its fork, 2.60-3.50 ; culmen, 2.25-2.55 ; 

 depth of bill through base, .45-.50 ; tarsus, 1.05-1.25 ; middle toe, .80-.86. 



This species has only a limited claim to a place in the fauna of North America. 

 It is a Mexican and Central American species, and occurs on the coast of California 

 only occasionally, irregularly, and very rarely. It was procured on the Pacific coast 

 of Mexico by Dr. Gambel, and was particularly common near Mazatlan. Dr. Cooper 

 could procure no evidence that this species ever occurs so far north as San Diego, in 

 California. Mr. Salvin obtained, at San Salvador, in Central America, a specimen of 

 this Tern, which he regarded as being absolutely identical with the typical S. elegans 

 from the Gulf of California. It was taken in December, 18G2. 



A specimen of the egg of this Tern — obtained at Guaymas, west of Sonora, 

 Mexico, by Captain Stone (Smithsonian Institution, No. 579) — measures 2.20 inches 

 in length by 1.45 in breadth. It has a ground-color of white with a pinkish tinge. 

 Its markings are quite bold and distinct, and are of a deep black and burnt sienna 

 color, with subdued shell-markings of lavender-gray. 



Sterna sandvicensis acuflavida. 



CABOT'S TERN. 



Sterna cantiaca, Am. On. Biog. III. 1835, 531, pi. 279 (not of Gmel. 1788) ; Synop. 1839,317; B. 



Am. VII. 1844, 87, pi. 431. — Coues, Key, 1872, 320 ; Check List, 1873, no. 564 ; 2d ed. 1882, 



no. 796. 

 Sterna (Tluitasseus) cantiaca, Coues, B. X. W. 1874, 673. 



Sterna Boysii, Xutt. Man. II. 1834, 276 (not of Lath. 1790, = cantiaca, Gmel.). 

 Sterna acuflavida., Cabot, Pr. Boston Soc. II. 1847, 257. — Lawr. in Baiid's B. N. Am. 1858, 860. 



— Baii;d, Cat. N. Am. B. 1859, no. 685. 

 Thalasseus acuflavidus, ( ouer, Pr. Philad. Acad. 1862, 540 (critical). 

 Sterna cantiaca acuflavida, Ridgw. Nom. X. Am, B. 1881, no. 683. 



