734 SYSTEMA TIC SYNOPSIS. — LONGIPENNES — GA VI^. 



heavy dark blotches. Kidification normally ten-estrial; reproduction altricial; young ptilo- 



pfedic. 



Analysis of Subfamilies. 



Bill epignathous, cered. (Jigers) Lesteidin^ 



Bill epignathous, not cered. (Gulls) Laeik^ 



Bill paragiiatlious. (Terns) Steekin.e 



Bill bypognatlious. {Skimmers) Khynchopix^ 



70. Subfamity LESTRIDiN>£ : Jagers, or Skua Culls. 



Covering of hill discontinuous, the upper inandi1>le heing saddled with a large horny 

 " cere," beneath the edges of which the nostrils opeu (unique, among water-birds) ; bill epigna- 

 thous. Tail nearly square, but the middle pair of feathers abruptly loug-exserted. Feet 

 strong ; tibi;e naked below, the podotheea granular or otherwise roughened behind, scutellate 

 in front ; webs full ; claws large, curved, acute. Certain pterylographic characters have been 

 already noted. A leading anatomical peculiarity in tlie large size of the ececa, as compared 

 with the cases of the (jther subfamilies. Another is that the sternum is single-iKjtched Ijrhind, 

 there being two notches on each side in the other subfamilies. There is but one genus, and 

 only four species are well determined. They belong more particularly tn the northern hemi- 

 sphere, although some also inhabit southern seas ; they mostly breed in boreal regions, but 

 wander extensively at other seasons. They iuhabit sea coasts, and also large inland waters ; 

 the nidilication resembles that of the gulls; eggs 2-3, dark-cidored, variegated. The sexes 

 are alike; the young dift'ercnt, excepting one species; there is also a particular melanotic plum- 

 age, apparently a miniial special condition. At first the central tail-feathers do not iiroject, 

 j, and they grow tardily. The skua gulls are eminently rapacious, whence their name of " jiiger'' 



i' (hunter) ; they habitually attack and liarass terns and the smaller gulls, until these weaker and 



f less spirited birds ari' fnrceil to drii]i or disgorge their prey. Their flight is vigorous ; lashing 



the air with the long tail, they are able to acconiplisli the rapiil and varied evolutions required 

 for the successful practice of jiiracy. Tims in tlicii' leailiug traits they are marine Eaptores ; 

 whilst the cered bill furnishes a curious analogy to tlie true birds of prey, 

 i 307. STEKCOKA'RIUS. (Li\t. stercorariiis, a nirdVfUixer.) Jagers. Character of the subfamily, 



as above. Tlie species of Merjulestris difiers decidedly from the rest, and migiit form a genus 



apart. 



Analysis of Species 

 Bill shorter tlian middle toe without claw ; tarsus shorter than middle toe and claw ; central rectrices little 

 projecting, l^oad to the tip. {Mefjatestvis.) 



Of great size, anil robust form. Bill about 2 inches long slua 764 



Smaller ; bill and tarsi relatively longer tlian in the foregoing, latter not shorter than middle toe and claw ; 

 central rectrices tinally la-ojecling far beyond the rest 



Central rectrices projectiiig about 4 inches, broad to the end pnmatorliiiius 705 



Central rectrices projecting about 4 inches, acuminate parasiUci:^ 7GG 



Central rectrices projecting 8-10 inches, acuminate bajpnii 707 



764. S. sku'a. (Fa^roese name.) Sku.4.. Bill shorter than the middle toe without the claw ; 



exceedingly robust ; width at base about equal to the height, wdiich is a third of the length of 

 I', culmen. Strias and sulci numerous and well marked. Encroachment of feathers on bill 



1 moderate, and nearly the same on both mandibles. Occiput scarcely crested. Wings only 



moderately long for this suld'amily ; the primaries very broad, and rounded at their tips. Tail 

 ' very short, broad, nearly even, the feathers truncated ; central pair projecting but little, and 



broad to their very tips, which are also truncated. Feet large and stout; tarsi shorter than 

 ;; the middle toe and claw. Size large ; form rtibust and heavy ; general organization very 



'[ powerful. Colors much the same over the whole body ; not subject to any very remarkalde 



iL' changes with age, sex, or season. Adult ^ 9 ; Latero-madial feathers elongated, rigid, witli 



ly lonsf disionnected fibrillas. Above, blackish -brown, more or less variegated with chestnut and 



