768 SYSTEM A TIG SYNOPSIS. — L ONGIPENNES — GA VI^. 



* 

 South America, questionably occurring in N. Am. ; " New Jersey and Long Island " (Audu- 

 bon). 

 803. S. aleu'tica. (Of the Aleutian Isles. Fig. 517.) Aleutian Tern. Adult : BiU of ordinary 

 shape, as in MrimdOg macrv/ra, etc., entirely black. Feet small, as in the species just named, 

 but the webs more deeply incised ; emargination not so great, however, as in Hyd/rocheUdon ; 

 much as in Halvplcma. Tibiae bare to the usual extent. Wings 

 and tail exactly as in Sterna proper, the latter, in its length and 

 depth of fork, recalling macrv/ra and forsteri. Crown and nape 

 black ; a large white frontal crescent, the horns of which reach to 

 the posterior border of the eyes, the convexity of which extends into 

 Fio. 517. — Aleutian Tern, ^^ nasal fossae, the concavity of which is opposite the anterior 

 much reduced. border of the eyes ; thus broader than in most species similarly 



marked. The black vertex sends through the eye a band that crosses the cheeks and reaches 

 the bin just posterior to the point of greatest extension of the feathers on the latter. The 

 chin, auriculars, and other parts of the head bordering this vitta below, are pure white, 

 presently deepening insensibly into the hue of the under parts. Tail wholly pure white ; no 

 pearly wash on either vane of any of the feathers. Upper parts at large dark pearl-gray, with 

 a dull leaden hue, different from the clear pearly of maerwa, etc., yet not of the smoky cast 

 of pamayensis, etc. ; it is a tint intermediate between these, that I find difficult to name satis- 

 factorily. The whole under parts, from the white of the chin, just noticed, to the under tail- 

 coverts, paler and more decidedly pearly, more nearly as in full-plumaged maarwra, yet more 

 grayish. Both under and upper tail-coverts, like the tail, white. The color of the back 

 mounts on the neck behind to the 

 black of the nape without interven- 

 tion of white. Under wing-coverts 

 and edge of wing pure white; as are 

 all the shafts of the primaries. Pri- 

 maries blackish lead-color, with 

 silvery hoariness, and each with a 

 large white space on inner web ; this 

 white space on the first primary oc- 

 cupies at the base the whole viddth 

 of the inner web, but grows nar- 

 rower toward the tip of the feather, 

 ending about an inch irom the tip, 

 which is wholly blackish lead-color, 

 this color running down as a narrow 

 margining of the inner vane for two 

 inches or more. On the other pri- 

 maries successively this white space Fig. 618. — Foot of Sooty Fig. 519. — Foot of Bridled 

 diminishes in size, and is also less Tern, nat. size. (From Saunders.) Tern, nat. size. (From Saunders.) 



distinctly defined. Secondaries colored much like the back, but the greater part of the inner 

 web of all white, and a narrow oblique touch of white on outer web near its end, which forms 

 a bar across the wing when closed. Bill along culmen 1.40 ; along gape 1.70 ; height at base 

 0.30; length of gonys 0.80; wing 9.75; tail 6.50; depth of fork 2.40; tarsus 0.60; middle 

 toe alone 0.80; its claw nearly 0.30. Alaska and Aleutian Islands ; a notable late discovery, 

 coming between the species of Sterna proper and the sooty tern group ; related to S. lunata. 

 804„ 8. fullgino'sa. (Lat. fuligimsa, sooty. Fig. 518.) Sooty Tern. Representing a small 

 group apart from any of the foregoing, named HaUplana by some ; approaching the noddies 

 slightly. BiU as long as head, scarcely exceeded by whole foot, straight, stout at base, taper- 



