34 Mr. Robert Collett on 



A. Specimens in Spring Plumage (March to May). 



a. Typical L. excubitor. 



One male. — No vermiculations ; basal spot on secondaries 

 large (29 mm.). Aker (Christiania), 2nd March, 1877. 



Two females. — One without, the other with, faint vermi- 

 culations; basal mark on secondaries normal (in $ short, 

 18-20 mm.) ; the white on first feather impure, being mixed 

 with black. Aker, 3rd May, 1881 ; 19th April, 1882. 



b. Nearly typical L. major. 



One male. — Vermiculations comparatively distinct ; indi- 

 cation of basal spot on secondaries occurring as a short 

 whitish-grey spot (10 mm.) on the third feather. Hamar, 

 17th April, 1885. 



c. Typical L. major. 



One male. — No vermiculations ; basal spot on secondaries 

 absolutely wanting; plumage worn, only a few new feathers, 

 Aker, 24th April, 1881. 



One female. — No vermiculations; basal spot on secon- 

 daries indicated only by an almost imperceptible sprinkling 

 of white on one single feather. Aker, 1st May, 1881. 



d. Intermediate between L. excubitor and L. homeyeri. 



One male. — Abdomen and rump entirely white ; first tail- 

 feather white, with the quills black in the middle ; basal spot 

 on secondaries long (30 mm.), extending beyond the coverts. 

 Guldalen, near Throndhjem, 1st May, 1881*. 



* This specimen approximates L. homeyeri more than L. excubitor. In 

 L. homeyeri the rump is described by some authors (Ibis, 1881, p. 51j as 

 grey, by the majority, however, as white — a striking proof of the difficulty 

 with which the characters admit of being determined in this as in the 

 other forms. In the specimen from Guldalen the said part and also the 

 abdomen and the tips of the secondaries are snowy white ; the inner 

 basal spot on the secondaries reaches to the middle of the feathers. 



Not improbably it was a similar individual that Seebohm has recorded 

 from Krasnoyarsk, and regarded as a hybrid between L. Icucopterus and 

 L. excubitor (Ibis, 1882, p. 421). 



