THE BIRDS OF HELIGOLAND 557 



occasions, both examples belonging to young autumn birds (junge 

 Herbstvogel) in which the aberrant form of the tail is rendered 

 specially prominent by the deep black markings at the tip, extend- 

 ing to a breadth of T10 in. (28 ??i?n.) forwards along the white of 

 the feathers. The first example was shot by Jan Aeuckens on the 

 25th of October 1847, in a very stormy north wind. Another, also 

 very pretty young individual, was shot after a long interval on the 

 28th of October 1883, and a similar bird was seen on the 10th of 

 November of the same year. The latter was, however, not shot, 

 though there cannot be the least doubt as to its identity, for it was 

 seen by the two best observers on the island Jan and Glaus 

 Aeuckens independently of one another, flying at a small distance 

 seawards from the edge of the cliff. They were, however, unable, or 

 rather unwilling, to shoot the bird, as it would only have fallen into 

 the violent surf deep down below, and been destroyed. 



The nesting stations of this gull extend from the Taimyr 

 Peninsula eastwards through northern Asia and Arctic America 

 as far as Greenland. It has also been met with on Spitzbergen. 

 According to Seebohm it has occurred from twenty to thirty times 

 on the coasts of England, Scotland, and Ireland. 



361. Cuneate-tailed Gull [ROSSE'S MOWE]. 

 LARUS ROSSII. 1 



Larus Rossii. Nauinann, xiii. ; Blasius, Nachtrage, 270. 



Cuneate-tailed Gnll. Dresser, viii. 343. 



Mouette de Ross. Schlegel, Krit. Uebers. d. Vogel Europas, p. cxxvi. 



Whereas Larus sabinii was distinguished from all other gull 

 species by its deeply furcate tail, the characteristic feature of 

 Ross's Gull is the equally aberrant pointedly cuneate form of the 

 same organ. Each pair of feathers of the latter from the outermost 

 pair is several millimetres longer than the preceding pair, while the 

 central pair projects far beyond all the rest. Thus, whereas the 

 former species, though a true gull in its general structure and 

 character, yet in one of its external features exhibits an approach 

 to the Tern family, the present species, whilst in all other respects 

 equally conforming to the gull type, may be said to possess the form 

 of tail peculiar to the predaceous gulls or Skuas. Neither species, 

 however, beyond this peculiar conformation of the tail, exhibits any 

 further relationship to the two genera of birds mentioned, just as, 

 among these latter, forms exist in which the forked or cuneate 



1 Rhododethia, rosea, Macgillivray. 



