LARID.E — STEllXINJ^ : TERNS, SEA SWALLOWS. 1017 



S. anaesthe'ta. (Gr. dvaiadriTOi, anaisthetos, stolid, stupiil, insensate, apathetic. Fig. 700.) 

 Bridled Tern. Paxayan Tern. Form of S. fuliginosa, but webbing of toes less extensive 

 (almost as deeply incised as in Hi/drochelidon). Adult (J 9 > iu summer: Bill and feet black. 

 Crown and stripe through eye to nostril black. A white frontal lunula, narrower than in fuli- 

 ginosa, extending beyond eye. Black pileum sharply defined on nape against ashy-white, 

 which insensibly shades into cinereous-brown, the prevailing color of the upper parts. Wings, 

 especially primaries, darker than rest of upper parts, with scarcely a shade of cinereous; tail, 

 with its coverts, much lighter and more ashy, approaching nape in color. Primaries with well- 

 defined, pure white spaces running for a considerable distance from their bases along inner 

 webs (in fuliginosa these webs simply grayish-brown with no well-marked wedges). A large 

 part of inner webs of secondaries white ; under wing-coverts white. Middle tail-feathers 

 brownish-ash, concolor with their coverts ; lateral ones with much white toward their bases, 

 especially on inner webs, increasing on each feather successively to such an extent that the 

 next to the outer one is wholly white except a small space at its tip, while the outermost is 

 entirely white. Shafts of primaries brownish-black above, white beneath ; of rectrices dark 

 along the cinereous and white along other portions. Under parts entirely white. Length 

 14.()0-1.'5.00; wing 10..50; tail G.00-7.00, forked about 3.50; bill 1.40-1.60; height at base 

 0.3.3-0.40; width slightly less ; tarsus 0.85 ; middle toe the same, with claw 1.20; outer toe 

 and claw 1.00; inner 0.75. Immature: Black cap imperfect, largely mixed with white on 

 vertex, so tliat it fades insensibly into the while of lunula, which latter is thus undefined ; black 

 bridle correspondingly imperfect. Upper parts paler and grayer tlian in the adult, some of the 

 feathers maciiined witli whitish. Lateral rectrices not wholly white. Under parts pure white, 

 as before. This is not the youngest plumage, but one that closely resembles, if it be not iden- 

 tical witli, tlie ordinary winter plumage of the adult. Young : As before; but more white on 

 head ; whitish tips of most feathers of the mantle ; a dark band along lesser wing-coverts, less 

 white on outer tail-feathers ; still younger, with rufous tips of the mantle feathers, but under 

 ])arts white from the first fiedging ; bill and feet browni.sh. This perfectly distinct .species in- 

 liabits most warm parts of both hemispheres ; West Indies, and casually Florida. It has many 

 synonyms, among them Haliplana discolor Coues, 1864. The absurd specific name was origi- 

 nally misspelled anaethetus by Scopoli, 1785 — a misprint perpetuated by the A. 0. U. I 

 made it anosthreta in 1st edition of the Key, 1872, after cmosthcetus Gray, 1871 ; but this is as 

 bad spelliui^f as almost any other. The word appears as anfrstlictica in the Key, 2d-4th edi- 

 tions, 1884-90; this is an improvement, but ancestheta is perfectly good Latin form, as a trans- 

 literation of the Greek, and no doubt what was (triginally intended. I used this form in 

 I> X. W. 1874, ]). 701. S<tme autliors have perpetrated aenothetus and anastaetus ! 

 IIYDROCHELI'DON. (Gr. vSup, hudor, water; xf^'^wj/, chelidon, a swallow.) Black 

 Tr.UN.s. l}ill a little shorter than head, longer than middle toe and claw, very slender and 

 acute : culmen and commissure convex, the curvature increasing toward tip ; outline of rami 

 and gonys both concave, the former most so ; angle very acute. Wings extremely long, 

 pointed, of same color as back, without distinct markings. Primaries broad and not acute ; 

 secondaries not slender nor fiowiug, reaching iu the folded wing only half-way to tip. Tail 

 .short, only moderately emarginate, the lateral feathers little exceeding the next, not streaming ; 

 all broad and mimded. Feet .^ilender and short ; tarsi rather less than middle toe. Toes mod- 

 erately long ; webs narrow ami very deeply incised (fig. .51). Size small ; form delicate ; ctdors 

 mostly black, the wings and tail jdumbeous. A small genus of 3 species, a subspecies of one 

 of which is common in Xortli America, where a second species has occurred as a straggler; the 

 third is the Whiskered Tern, H. hyhrida. 



