438 LARIDA 
comparable to those of the preceding bird, take place, 
maturity being reached about the fifth year. 
BEAK. Yellow, red at the angle. 
Freer. Flesh-colour. 
IRIDES. Straw-yellow. 
AVERAGE MEASUREMENTS. 
TOTAL LENGTH ... 29 in. Female smaller. 
WING .... oe me See 
BAKE i ae. i” Gn 
TARSO-METATARSUS _... BS 
Eee eas ah Soar. a Betas 
Allied Species and Representative Forms.—L.  schisti- 
sagus,' of Stejneger, occurs in Behring and Okhotsk Seas. 
It is on the whole smaller and lighter on the back and 
wings than L. marinus. 
GLAUCOUS GULL. Larws glaucus (O. Fabricius). 
Coloured Figuwres.—Gould, ‘ Birds of Great Britain,’ vol. v, pl. 
57; Dresser, ‘ Birds of Europe,’ vol viii, pl. 605; Lilford, 
‘Coloured Figures,’ vol. vi, pl. 26; Booth, ‘ Rough Notes,’ 
vol. iii, pl. 38. 
The Glaucous Gull,’ another magnificent sea-bird which 
almost equals the great Black-backed Gull in size, is an 
autumn and a winter visitor to our shores from more 
northern latitudes, occurring chiefly in severe weather. 
A certain number appear to remain until spring, especially 
in North Britain, where the species is most frequently met 
with. In the Shetlands it has been observed as late as 
June,’ but has never bred there (Saunders). In the Solway 
' According to Mr. Saunders ‘“‘ L. schistisagus has no close affinity 
with L. marinus, but rather inclines to the Herring-Gull section” (Cat. 
Birds Brit. Mus., vol. xxv, p. 260). 
* Dr. Lawrence Edmonston first introduced it to notice as a British 
bird, having obtained young individuals in the Shetlands in 1809, 1814, 
and up to 1821, when he proposed naming it Larus islandicus. In 
March, 1821, he described an adult bird. 
* Jn Ireland, three instances of its occurrence in July, are stated by 
Thompson (Nat. Hist. Irel.). 
