38 August Brinkmann. 
that the intestine was very distended. Some years D. urogalli 
can be extraordinary common, in Søndfjord in 1912 the parasite 
was found in 90 % of all birds examined. | 
The thread-worms are represented in the Willow Grouse by 
two species, one of them being very rare, namely the Trichosoma 
longicolle well known from the Red Grouse. I found the worm 
only twice and in very few numbers. (On one occasion 7 of these 
parasites were found in the duodenum of the Ptarmigan (Lagopus 
mutus, \.)). 
The other thread-worm is a very common one, it is the Heterakis 
magnipapilla described from Tetrao tetrix by v. Linstow. 
This parasite, which can infest an animal in numbers over 
100, has a very curious distribution in Norway; not a single speci- 
men being found in about 60 birds from the coast districts; the 
eigth birds infested with the parasite all came from central Norway, 
and we know, that the worm is extremely common in all eastern 
districts of the country. As far as our present experience goes 
the Heterakis magnipapilla may be a form with eastern distri- 
bution in Europe, known from eastern Prussia and eastern 
Norway only. 
