48 



Mini) (;\i.i,i;k^'. 



species are exliibitcd, one f)f tlic most uotewortliy bciii^ tlir- Paritic (ruU 

 {Gadiaiinspac/ficux) (417), with its remarkably stout bill; while Tschiuli's 

 [('iiH' I'd.] (430), Ilemprich's (431), and Heerman's (429) Gulls arc specially inte- 

 resting forms on account of their peculiar dusky coloration. The hooded 

 gulls comprise such species as our Blaek-hcaded Gull [L. ridibundus) 

 (432), the commonest British species, and the Bonaparte's {L. phi/a tffl- 

 phue) (434), Mediteri-ancan Blaek-lieaded [L. melanocephalnx) (435), 

 (ireat Hooded {L. ic/il/iijartns) (436), and Little Gull [L.mlntdus] (437), 

 all accidental visitors to Britain. In these birds the black hood is only 

 assumed during the breeding season, at other times the head is white or 

 nearly so. Sabine's Gull [Xeiiui suhinei) (438) and the very rare Ross' 

 Rosy Cxull {Rliudostetlihi rosea) (439) arc aberrant forms; in the former 

 the tail is forked, in the latter euneatc or wedge-shaped. Both belong to 

 the Arctic Seas and are only stragglers to our coasts. 

 [Case L'6.] 'J'he Terns or Sea-Swallows may l)c recognised by their nearly straight, 

 pointed and comparatively slender bill, forked tail, and more slender 

 build. S])ecially interesting forms arc the \Vhite Tern [Gyc/is comlidu) 

 (440) and the Noddy [Aiwiis .slo/hlus) (443), with its curious nest of 

 mud and scaw ced, etc. placed on the bough of a tree. This bird has twice 

 been recorded from our shores. In the IJiitish Islands five species of Tern 

 {SleriKi), viz. : the Common [S. fluviutilh) (452), Arctic (,S'. niacrura) 

 (453), Little (>'. miimla) (448) , Sandwich (,S'. cantiaca) (455) [PI. VIII.], 

 and Roseate (,S'. doityalU) (454), are regular summer visitors and 

 remain to breed, the latter being very mucli the rarest. Besides these, 

 seven other species of Tern have been recorded as accidental visitors, 

 viz.: the Sooty {S. fidii/iiiosii) (446), Bridled (S. (nuestfic/a) (447), 

 Caspian ( lli/droprof/nc casjt//i) (456), (iuU-billed { Geloc/iclidoii aiii/licd) 

 (457), White-winged {Hi/droc/ii/idoii k'liroptcra) (458), Whiskered 

 { II. hyhrida) (459), and Black (7/. /»>//•«) (460). All these arc repre- 

 sented in the Case, and the last-named may be considered a regular 

 visitor and formerly bred in England. 



The most remarkable members of the family arc the Scissor-billed 

 Terns, of which an e.Kample will be found in liliijtirliojis Jlaviroslr/s (462). 

 They have been given their trivial name on account of the peeuliai 

 form of the bill, which is quite iuii(jue among birds. Both upper and 

 lower mandibles arc compressed to a knife-like thinness, and the lower 

 is produced beyond the upper for a considerable distance. This peculiar 

 modification appears to be for the purpose of catching fishes from 

 among the surface-swimming shoals. The lower jaw being used as u 

 sort of plough, catches up the prey as the bird flies along over the 

 surface. Five species are known, of which one is Asiatic, one African, 

 and three are Amei'ican. 



