698 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



its fork being less than one-fourth of length of tail, six middle 

 rectrices being almost equal in length, only three lateral ones on 

 each side elongated. Feet short, tarsus much shorter than bill. 

 Wings long and pointed. One species, one subspecies, which, 

 however, requires further elucidation. 



HYDROPROGNE CASPIA * 



537. Hydroprogne caspia (Pall).— THE CASPIAN TERN. 



Sterna caspia Pallas, Novi Coram. Acad. Petr., xiv, i, p. 582, pi. xxii. 



(1770 — Caspian Sea, S. Russia). 



Sterna Tschegrava Lepechin, Novi Comm. Acad. Petr., xiv, i, p. 500, 



pi. xiii, Fig. 2 (1770 — Caspian Sea, S. Russia). 



Sterna caspia (Pallas), Yarrell, in, p. 536 ; Saunders, p. 641. 



Sterna tschegrava Lep. Hand-List (1912), p. 192, 



Description. — Adult male and female. Winter. — Fore-head, crown, 

 and nape white closely streaked black, width of streaks varying 

 individually, but always narrowest on fore-head and widest on 

 nape ; under eye and ear-coverts mostly black, feathers with white 

 bases and varying amount w T hite fringes, in front of eye sometimes 

 similar but usually streaked as fore-head (feathers on nape some- 

 what elongated) ; back of neck white ; rest of upper -parts, wing- 

 coverts, and secondaries ash-grey with silvery tinge, but rump, 

 upper tail-coverts, and tail rather paler and sometimes almost 

 white ; whole under -parts white ; primaries with tips, outer webs, 

 and outer part of inner webs silver-grey, rest of inner webs dark 

 grey, bases paler extending in ill-defined wedge-shape toward tips, 

 shafts straw-white ; primary-coverts silver-grey. N.B. — Exposed 

 portions of primaries become blacker by wearing off of silvery radii, 

 rami being brown-black. This plumage is acquired by complete 

 moult Aug.-Nov. sometimes finishing Dec. Summer. — Another 

 complete moult takes place Jan.-ATar. As winter but fore-head, 

 crown, and nape and upper -part of lores, line under eye and upper 

 ear-coverts glossy, greenish-black ; lower part of lores and lower 

 ear-coverts white as rest of under -parts. 



Nestling. — As hi Gull-billed Tern upper -parts varying dull buff 

 to buriish-grey, but with fewer brown-black markings, these being 

 confined to small spots or specklings on upper -parts but not on 

 crown and neck, which are unspotted with base of down dark 



* It has been decided, for the sake of uniformity, in cases where names 

 are in dispute, owing to different opinions in the interpretation of the Inter- 

 national Rules, to adopt in this book the names decided upon by the majority 

 of the B.O.U. List Committee, whether we are in personal accord with that 

 decision or not. For this reason the name caspia is used for this bird. 



Lepechin's description and figure are quite clear, but his name has been 

 rejected because not all of Lepechin's names were binomial, but in my 

 opinion they should be accepted as he seemed to be generally binomial in 

 principle. If names were rejected because of some backslidings in the 

 authors' publications all names of Boddaert (often not binomial !), Hermann, 

 Briinnich, and others, could not be accepted ; their rejection would cause 

 great confusion. — E.H. 



