71 
(nebst einem Beitrag zur Bachfauna von Bornholm). Mitteil. 
Naturw. Ver. f. Neuvorpommern u. Rugen 38. Jg. 
Ussing, N. V. 1913. Danmarks Geologi. Tredie Udg. ved P. Harder. Danm. 
Geol. Unders. III. R. Nr. 2. 
Wahlgren, E. 1908. Bidrag till kånnedomen om Ofre Klaralfdalens Entomo- 
geografi. Ark. f. zool. Bd. 4 N:o 13. 
1910. Xeroterma relikter i Olands alvarfauna. Fauna och Flora 
1910. (Uppsala & Stockholm.) 
1915, 1917. Det olandska alvarets djurvarld I, II. Ark. f. zool. 
Bd. 9, 11. 
Wallace, A. R. 1892. Island Life. Sec. Ed. (London.) 
Warming, E. 1914. Om Bornholms Plantevækst. Botan. Tidskr. udg. af Dansk 
Bot. For. Bd. 33. 
Winge, H. 1904. Om jordfundne Pattedyr fra Danmark. Vidensk. Medd. 
Naturh. Foren. København 1904. 
se Danmarks Fauna. 
Zacher, F. 1917. Die Geradfliigler Deutschlands. (Jena.) 
Summary. 
Planaria alpina in Bornholm. 
In August 1918 I found the arctic-alpine Planarian Planaria 
alpina in four cold streams in the north-eastern part of the island 
of Bornholm (cf. the map. fig. 1). I examined numerous streams 
in the whole island, but found this animal only in the northern 
part, in water of 12,7—14,2 0 C. temperature. In the flat Southern 
part of the island the streams are too warm in summer for this 
stenotherm cold-water species. The largest specimens observed had, 
when alive, a length of 10 mm. 
Four of the five localities — in one of the four streams I 
found the animal in two places, at the source and near the mouth 
— are situated below the uppermost late-glacial limit and below 
the uppermost Litorina-limit. The animals have evidently migrated 
down towards the mouth since the Litorina transgression. 
Planaria alpina was previously known from the Southern Baltic 
area; it is found in Rugen (Thienemann) and in Moen (Brink¬ 
man n). In Bornholm as well as in these places, it is a glacial 
relic. The discovery of this species in Bornholm, 37 km from 
9 
i i 
