E. LÖNNBERG, HYBRID GULLS. O 



maries as well as the white markings on the tips of the 

 same appears to be somewhat variable in these hybrids. On 

 a sketch of the left wing of a hybrid, which not yet has 

 assumed the plumage of the mature (fig. 1), it is to be seen 

 that the black extends far down, at least on the outer web 

 of the three first primaries, and gradually shades into dark 

 grey. The first primary has a subapical, longish, white spöt 

 on the outer web, the second none at all, and the third a 

 small apical spöt. On the fourth to sixth or seventh pri- 

 maries there is a subapical dark band inside an apical white 

 spöt of fair size. These bands are not quite black, however, 



Fig. 1. Primaries of left wing of an Fig. 2. Primaries of left wing of 



immature Larus fuscus ef X L. leu- an adult Larus juscus (f X L. leu- 



copterus 9 • copterus 9 • 



and become gradually paler towards the inner primaries, 

 although a distinct, transverse band can be plainly seen even 

 on the seventh primary. The scarcity of white and the ab- 

 sence of »mirrors» on the first primaries are especially to 

 be noted in this specimen, but it may be due to the imma- 

 turity of the bird. 



Another sketch of the left wing (fig. 2) of a hybrid in 

 full plumage (now unfortunately dead and löst) from the 

 26th of Sept. 1916 displays black orily on the four first pri- 

 maries.^ The two first primaries have broad black tips and 



^ It is not excluded that the fifth was in moult, and that this fact 

 was not observed bv the artist. 



