10 ARKIV FÖR ZOOLOGI. BAND 12. N:0 7. 



that Larus glaucus and Larus leucopterus should occasionally 

 hybridise, which, however, might be very difficult to prove 

 as these GuUs are so similar inter se. Suchetet does not 

 mention any hybrids between different species of Larus in 

 his work: »des hybrides å Fétat sauvage» (1897). 



Nevertheless hybrids have been produced between Larus 

 glaucus and Lariis marinus in the Zoological Garden in Copen- 

 hagen, and this last year 1918 also at »Skansen», Stockholm. 

 About 1896 such hybrids were rather numerous in the Zool. 

 Garden of Copenhagen, and the present author, who had had 

 the opportunity of seeing them, mentioned their existence 

 in a short note in a Swedish sporting journaU together with 

 notes an other bird-hybrids. 1 was told that a male Larus 

 marinus had year after year mated with a female L. glaucus, 

 and thus become the progenitor of a numerous hybrid off- 

 spring. About the appearance of these hybrids I wrote (1. c.) 

 that the hybrid product mostly resembled L. glaucus, be- 

 cause the colour of the mantle was bluish grey. In certain 

 specimens some scattered, dark feathers were mixed in among 

 the grey of the back. The mos t conspicuous inheritance 

 from L. marinus consisted therein that the distal parts of 

 the primaries were black with the tip w^hite, and I pointed 

 out the importance of this fact, because such a pattern was 

 of a common occurrence among Gulls. 



A couple of years låter, 1899, Mr. H. Winge of the 

 Zoological Museum Copenhagen published a note^ on a G ull 

 in his keeping, which he regarded as a hybrid between Larus 

 marinus and L. glaucus. This specimen had been collected 

 at Upernivik the 8th of Sept. 1886. Winge points out that 

 the back of this Gull is much paler than in L. marinus, 

 almost as in L. glaucus, but the primaries as in L. marinus 

 (or as he adds in a letter partly lighter). He mentions also 

 its resemblance with the hybrids produced in the Zoological 

 Garden of Copenhagen between the species mentioned, and 

 adds that it reminds about Larus nelsoni Henshaw, which 

 Winge also suspects to be a hybrid. 



^ »Om några fågelbastarder», Sv. Jägarförb. nya tidskr., 35 årg., 1897, 

 hft 1, p. 15. 



' In »Grönlands Fugle», Meddelelser om Grönland, Kjöbenbavn 1899, 

 p. 180. 



