224 Proceedings of the Boyal Physical Society. 



forms, one of them (S. violaceus) being hitherto known only 

 from Finland, another (/. spitzbergenensis) only from Spitz- 

 bergen, and a third {A. longispinus) till lately only from 

 Novaya Zemlya. 



Comparing onr list of Collembola with the lists of 101, 

 89, and 80 forms — a number of which, however, are not 

 in our opinion really distinct — recorded from Scandinavia 

 (6, 15), Finland (11), and the country around Hamburg (13), 

 respectively, it appears that only eight of the Edinburgh 

 species are unrecorded from Scandinavia, as against ten 

 absent from the Finnish list and fourteen from the Hamburg 

 one. Most of our species are widely distributed over the 

 Palsearctic region, and several of them extend their range 

 far beyond its limits — indeed, the exceedingly wide distri- 

 bution of some forms is peculiarly interesting. The range of 

 Sminthurus hortensis, for example, extends from Scandinavia 

 and Scotland to Japan on the one hand, and America (both 

 North and South) on the other ; Isotoma palustris ranges 

 from Novaya Zemlya and Siberia to Bismarck Archipelago, 

 throughout Europe to the Azores, California, and La Plata ; 

 while outside of Europe Achorutes viaticus is recorded from 

 places as far apart as Greenland, Behring Island, and Tierra 

 del Fuego. The absence of Orchesella villosa (one of our 

 rarer species) from the Sandinavian and Finnish lists seems 

 to show that it is a more decidedly southern form than most 

 of the others. Papiriics ornatus (a common form with us) has a 

 very similar range, only it goes up to the western (Norwegian) 

 side of Scandinavia. Anurida mctritima, and the Thysanuran 

 Machilis maritima, neither of which are in the Finnish list, 

 are apparently confined to the shores of the Atlantic. 



It is difficult to say exactly how many species have been 

 recognised in the British Isles. Ptoundly the number may 

 be stated at about seventy-five Spring-tails and four Bristle- 

 tails (excluding one or two foreign importations); of these, all 

 the latter, but only sixty-three of the former, have as yet been 

 detected in Scotland. But seeing that the Collembola are 

 a hardy race, and so largely represented in Northern Europe, 

 we have every reason to anticipate that future investigations 

 will add materially to the list of Scottish species. 



