1905.] HYBRIDS AMONG NORWEGIAN BIRDS. 23 



Upon the vvhole, the distribution of colour in this specimen, 

 which may be assumed to be wearing the normal winter plu- 

 mage of the male, is almost exactly the same as in the other 

 hybrid, and it is therefore natura! to suppose that here too it is 

 the smaller, L. mutus, that is the father, and L. tetrix, fem. the 

 mother. As in the other hybrid, the claws are long and like 

 those of a ptarmigan, while the last joint is covered with scales; 

 and the base of the feathers in the black parts of the head and 

 neck are of a dark chestnut colour. 



Total length (to the end of the outermost tail-feather) 438 mm 

 Length to the end of the middle tail-feathers . . . 430 r 

 Length of the wing (from carpus) 219 c 



)mm 



Length of the outermost tail-feathers 115 mm 



'n 



Length of the middle tail-feathers 106 mm 



A full description, with accompanying figures, of both 

 the above bastard forms, has been given by me in the «Ber- 

 gens Museums Aarbog" for 1897, No. 7, Pl. I— III; Bergen, 

 1898. 



6. Lagopus lagopus, (Lin.) X Lagopus mutus, (Mont.) 

 (mas?) (fem.?) 



Occurrence. A single specimen in autumn plumage, caught 

 at Tromsø, August, 1906, appears to belong to a hybrid between 

 the hvo Norwegian species of ptarmigan (Rype-Bastard). 



Dicign. Size, bill and bodily proportions about intermediate be- 

 tiveen those of the two parents 1 . 



Adult (male?), summer-autumn plumage. The colour an inter mixture 

 of the autumn plumage of the hvo species (as a rule, each single feather 

 of mingled colours); head, throat, belly and sides resemble more or less 

 L. lagopus, the back, upper tail-co verts and breast, L. mutus. 



The throat of a reddish colour, unspotted; the upper sur face of the 

 head and the nape with narrow, whitish cross bars. The entire upper 

 surface with reddish grey and whitish narrow cross bars; the belly with 

 broad black cross bars on a pale reddish grey ground. 



1 The relative lengths of the wing-feathers cannot be stated, as the 4*^ 

 and 5 th were in process of moulting. 



