THE BIRDS OF HELIGOLAND 299 



than the fifth, fourth, and third, and the outer pair -12 in. (3 mm.) 

 shorter than these latter. All the feathers are drawn out to a 

 point at the shaft, a conformation produced by the shallow sinua- 

 tion of the inner web. 



The name S. borealis is a particularly fitting one in the case of 

 this bird, for of no other species of this family are the nesting 

 quarters so exclusively confined to the higher latitudes. They 

 extend from 70 20' N. in Fimnark; within the same parallels, 

 along the Arctic coasts of the whole of Asia and across to Alaska. 

 Middendorff met with the bird on the Lower Boganiida, and the 

 Vega Expedition found it numerously on the coast of the 

 Tchuktchee peninsula. 



113. Greenish Tree Warbler [GRUNER LAUBVOGEL]. 

 SYLVIA VIRIDANA, Blyth. 1 



Phylloscopm viridanus. Seebohm, Cat. of Birds of Brit. Mus., v. 44. 

 Greenish Tree Warbler. Jerdon, Birds of India, ii. 193. 



This East Asiatic species, hitherto strange to Europe, I have 

 obtained in Heligoland three times. The first example, a young 

 bird, on the 25th of September 1878 ; afterwards a fine male, shot 

 by my son Ludwig on the 30th of May 1879 ; and lastly, on the 

 3rd of June 1880, 1 had the pleasure of shooting a beautiful female 

 in my garden. The two last examples are perfectly uninjured; 

 the first is much damaged, but nevertheless preserved with the 

 other two in my cabinet. 



It should in this place be noted, that the male bird shot in 

 May had, in the fresh condition, olive grey feet, and may accord- 

 ingly have to be placed under S. plumbeitarsus (Swinhoe). It 

 exhibits, however, no further difference of any kind from the two 

 other examples, and I therefore do not propose to describe it as a 

 separate species on account of a peculiarity which is no longer 

 evident in the dried example. 



The fact of its having occurred here three times within so short 

 a space of time might suggest the thought as to whether this may 

 not be the same Warbler met with by Collett in Upper Scandi- 

 navia, especially as in its external appearance it closely approaches 

 S. borealis. However, after receiving one of Collett's examples, I 

 do not consider this suspicion warranted by the facts. 



In its general appearance this species bears a strong resemblance 

 to the preceding, S. borealis. The bill, however, is much smaller, 

 in fact a typical Warbler's bill ; whereas this organ is, in S. borealis, 



1 PhyUoscopus viridana (Blyth). 



