The relationship between the palaearctic and nearctic faunas 263 



Brown) were confused under "tessellata" in North America. At least specimens from New- 

 foundland belong to a third species. 



7. Caenoscelis. Through the courtesy of Mr. Vibe I have been able to study 3 specimens 

 collected by him in Greenland. They agree with the descriptions of cryptophaga Reitt. 

 (187s, p. 87; 191 1, p. 66). A comparison with a typical specimen (from "North America") 

 would however be desirable. In Casey's key (1900, p. 104-107) they run to macilenta Csy. 

 (New York, Penns.) which is probably a synonym. At least I have ventured to give the distribu- 

 tion as "E. North America". 



8. After the above was set up for print the Greenland Dorytomus has proved to be 

 distinct from taeniatus and probably a Nearctic species. 



The Nearctic element (including two Holarctic species lacking in Europe) 

 amounts to 6 species only:^ 



Colymbetes dolabratus groenlandiciis Caenoscelis ? cryptophaga 



Gyriniis opacus blairi Simplocaria tessellata 



Micralymma brevilingue Coccinella transversoguttata 



Of these only the Micralymma is flightless. It inhabits the tidal zone and is no 

 doubt easily dispersed by sea-water drift (cf. M. marinum, p. 244). 



This point of view provides a satisfactory explanation for the unequal share 

 of Nearctic species in Greenland within the diff"erent groups of animals to which 

 attention was drawn above. They are most numerous in Macro-Lepidoptera (35 

 per cent) and Birds (28 per cent), with more or less developed powers of active 

 flight, in the second place among Spiders (22 per cent, or 36, if "endemic" species 

 are included), with their common habit of "ballooning" into the air. But in 

 Collembola (Spring-tails) the Nearctic species amount to 11 per cent only, con- 

 siderably less than in Coleoptera. Among comparatively able flyers, as the Tricho- 

 ptera (Caddies-flies), 6 of 9 (or 10) species are Nearctic (Henriksen, 1939, p. 23-24; 

 Vibe, 1950) but the Neuroptera (Lace- wings) , with poorly developed powers of 

 flight, are represented by one Holartic and two Palaearctic species. 



The composition of the coleopterous fauna of Baffin Island is in complete 

 accordance herewith. Of the 16 species^ known so far from this island (Brown, 

 1937), only three species are common also to Greenland: the Water-beetles 

 Colymbetes dolabratus groenlandicus and Hydroporus melanocephalus, both good 

 flyers, and the Staphylinid Micralymma brevilingue, just mentioned as easily 



^ After the above was written, the Dorytomus from Greenland has proved to be a prob- 

 ably Nearctic species, different from taeniatus F. {vide table 7). It is fully winged. 



^ From Ellesmere Island in the high north (between about 76° and 83° north) only 5 

 species of Coleoptera are reported (Brown, 1937, and in litt.). Two, of the genera Crypto- 

 phagus and Enicmus, are accidental importations and the Quedius "fulgidus", according to 

 earlier practice of nomenclature within the genus, is no doubt mesomelinus Mrsh., a true 

 synanthrop, common in the dwellings of the West Greenland esquimos. The two remaining 

 species are Micralymma brevilingue Schio. and one Atheta, which has been investigated 

 by Dr. Brundin, who informs me that it represents a species unknown to him, possibly 

 undescribed (unfortunately a female), and thus almost certainly a Nearctic element. 



