28o CHAPTER III 



possible high-arctic route of migration, Greenland-Spitzbergen, assumed by some 

 authors (for instance Hansen, 1930, p. 226; Nordhagen, 1935, p. 157), to which 

 zoologists seem to be unable to make a contribution. 



Affinities in the south 



Animal distribution shows a few spectacular instances of subtropic or "low boreal" 

 forms indicating faunistic relationship between the southern parts of North 

 America or the West Indies and Europe, including adjacent regions of North 

 Africa and western Asia. 



Usually the forms in question are not identical. Possible exceptions are two 

 Carabid beetles, Nomius pygmaeus Dej. and Blethisa eschscholtzi Zoubk., and one 

 Wood-louse (Terrestrial Isopod), Tylos latreilli Ad. & Sav. The latter inhabits 

 the epilittoral zone of the sea-shore of the Mediterranean region and the Atlantic 

 coast, north to central France, south to Dakar; on the American side, Florida, At- 

 lantic Central America, the Bermudas and West Indies. Contrary to Vandel (1945, 

 p. 229), I find the most probable explanation of this disjunct area to be introduc- 

 tion with ships from Europe into America. The habitat of the species quite invites 

 transport. 



The Centiped Theatops erythrocephalus C. L. Koch, from southern Europe, 

 mentioned by Schmidt (1946, p. 145) as indigenous in western U.S.A., is no 

 doubt introduced in the latter area. 



One would perhaps feel inclined to apply the same view to Nomius pygmaeus, 

 the more so since, in North America, it has repeatedly been observed in villages 

 and towns, even indoors, as a famous "stink beetle". In the Old World it is a grand 

 rarity and the assumption just mentioned would then necessarily imply introduc- 

 tion /rom North America. This, however, has become less probable since Basilewsky 

 (1954) has described a very closely related species, N. schoutedeni Basil., from 

 Ruanda Urundi in the interior of Belgian Congo. Now Nomius belongs to a 

 quite isolated group (usually termed Tribus) among the Carabidae, the few genera 

 of which have a pronouncedly disjunct, obviously relict, distribution, with several 

 representatives in Australia (Emden, 1936, p. 50-51; Jeannel, 1941, p. 290-292). It 

 may be suggested that not only subtribes and genera of this group, but also the 

 actually existing species, are very old and the present distribution of Nomius 

 pygmaeus may be regarded as a disjunct relict area which in itself gives no clue 

 to the history of the species. 



The same may be true for Blethisa eschscholtzi (fig. 56). One single specimen is 

 known from North America, vicinity of Sanderson, SW Texas, but there seems 

 to be no reason to doubt the correctness of the locality label or the indigenous 



