The relationship between the palaearctic and nearctic faunas 



255 



^ 



(Photo P. Ardo.) 



FIG. 39. Approximate distribution of Simulium vittatuni Zett., a species of gnat or 

 "black fly", a regular nuisance to man and cattle. 



Mainly according to A. Stone (in litt.) who thinks the species may be a complex one. 

 The figured specimen is from Greenland. 



only slightly wider Davis Strait (350 km.). The Nearctic element of the Icelandic 

 insect fauna is less than one per cent! 



On the Faeroes, as a matter of course, it is still more insignificant, consisting 

 only of two of the Noctuid Moths just mentioned, Crino sommeri and Crymodes 

 exulis, and, among animals other than insects, of the freshwater Sponge Hetero- 

 meyenia ryderi Potts, treated above (p. 245). 



The fauna of Greenland, however, provides the great surprise within the chain 

 of islands across the North Atlantic. This large island, almost a continent of 

 more than 2 million square kilometers, though to more than four fifths covered 

 with ice, traditionally belongs to America. Actually, the shortest distance to 

 the North American mainland, in northern Labrador, is little more than half 

 (750 km.) of the distance to the European continent, in northern Norway 

 (1,400 km.). 



The American influence on the Greenlandic fauna, as on its flora, is quite 

 obvious but it is far from dominating. Above all it is striking how unequally large 

 is this element among diff'erent groups of animals. In those sufficiently known and 

 large enough to allow a comparative analysis, the share of the different geographical 

 groups is as follows: — 



