402 LAEID^. 



STEEXA. 

 Sterna, Linn. Syst. Xat. i. p. 227 (1766) ; Saunders, Cat. Birds Brit. ilns. xxr. p. 40 (1896). 



In the genus Sterna, whicli contains the true Tems, the tail is at least half the 

 length of the wing, and shows generally more than this proportion ; the onter tail- 

 feathers, which are the longest, are pointed. The tarsus is short, never exceeding the 

 middle toe and claw in length. The bill is compressed and slender. 



The genus is cosmopolitan in its range, and includes more than thirty species. 

 Mr. Howard Saunders unites, under the generic name Sterna, all the Little Tems 

 (Sternula) and the Sooty Tems (Onychoprion). The eggs vary in number from one to 

 three, and some of them are very similar to those of Limicolse. 



1. Sterna forsteri. 



SteriiafoTsteri, Xutt. ilan. Om. ii. p. 274, footnote ' ; Cones, Ibis, 1864, p. 390 ^ ; Salr. Ibis, 1866, 

 p. 199'; Scl. & Salv. P. Z. S. 1871, p. 569 ' ; Lawr. Mem. Bost. Soc. X. H. ii. p. 318 ' : 

 Bull. U. S. Xat. Mus. no. 4, p. 51° ; Sumielir. La Xat. v. p. 234 ' ; Baird, Brewer, & Eidgway, 

 Water-Birds X. Amer. ii. p. 292'; A. O. U. Check-1. X. Amer. Birds, 2nd ed. p. 24' ; 

 Saunders, Cat. Birds Brit. Mus. xxv. p. 46"; Gates, Cat. Eggs Brit. Mus. i. p. 180, t. 13. 

 fig. 4". 



Ptll. hiem. Supra margaritacea, pileo toto et collo postico albis; uropygio qaoque albo; Cauda matgaritacea, 

 rectricibns extimis albis, intns sordide cineraceis ; alia dorso concoloribus, secuiidariis albo terminatis ; 

 primariis apicem versus nigris, intus albis, rhachidibns albis ; loris, facie lateral! et corpora subtus toto 

 albis ; regione anteoculari et fascia lata postoculari nigris ; supercilio postico nigro maculato : rostro 

 nigro, apice albicante ; pedibus saturate aurantiacis ; iride bruunea. Long, tota circa 13-0, ate 9-4, 

 caudse 5-3, rectrice extima o-o, culm. 1-6, tarsi 0-9. (Descr. maris adniti ex Corpus Christi, Texas. Mus. 

 uostr.) 



Ptil. cestiv. Supra margaritacea ; pileo et nucha, baud cristata, et facie lateral! dimidiata nigris, macula 

 suboculari nigra ; loris et facie lateral! cum regione parotica et corpore subtus toto pure albis : rostro 

 aurantiaco, apicem versus nigro, apice ipso flavo ; pedibus aurautiaco-mbris. Long, tota circa 13-0, 

 alae 9-4, rectrice extima 6-S. (Descr. feminae adultae ex Corpus Christi, Texas. Mus. nostr.) 



Juv. adultis similis, sed brunneo adnmbrata, plumis singulis apicem versus paUide brunnescentibus. 



Eab. XoETH America generally, breeding from Manitoba southward to Virginia, 

 Illinois, Texas, and California^. — Western Mexico^", Mazatlan {Grayson ^^), 

 San Mateo, Yentosa Bay, Tehuantepec {Sumichrast^' ^^) ; GcTATEiiALA, Lake of 

 Duenas {0. S. - ^ * ^^). — South Amebica, oflF the coast of Pernambuco ^^. 



S. forsteri is distinguished from the other Tems of medium size, which have the 

 forehead black like the crown, by the colour of the long outer tail-feathers, in which 

 the outer web is white and the inner one is " darkish grey," as Mr. Howard Saunders 

 expresses it. 



This species is found in the interior, as well as on the coasts, of Xorth America, 

 frequenting grassy marshes *. In winter it visits Mexico and Guatemala, and was 

 found abundantly by Grayson along the shoves and esteros of Mazatlan, from October 

 to April ^. 



