90 ANNALS OF SCOTTISH NATURAL HISTORY 



E. arctomys, Ehr. (4), was recorded in error, in consequence of 

 Prof. Richters identifying as arctomys an animal which has v. 

 and vi. separate (E. mutabilis, E. suillus). 



E. mutabilis, Murray (6), is now considered by Prof. Richters as a 

 variety of E. suillus, Ehr. 



M. islandicus, Richters (14). This erroneous record is due to 

 carelessness. Had sufficient attention been given to the char- 

 acters of the claws the mistake would not have been made. 

 The animal thus recorded had claws of the Diphascon type, and 

 may have been M. lacustris or M. arcticus, the true islandiats 

 has claws sufficiently like those of M. hufelandii. 



ARCTIC SPECIES IN SCOTLAND. 



An important feature in the Scottish Tardigrade-fauna is the 

 strong Arctic element. Three-fifths of the Scottish species (30 

 species) occur also in the Arctic. It is still more important that 

 7 of the species are only known in Scotland and the Arctic (in one 

 instance also in the intervening Faroes). 



An affinity, geographical rather than climatic, is suggested by the 

 fact that 4 of the Arctic species are not found south of the Orkneys 

 and Shetlands. A climatic relation is, on the other hand, suggested 

 by the greater frequency of many of the Arctic species on mountain 

 tops in Scotland. 



ARCTIC SPECIES. E. s/iil/us, islandicus, wendti, spitsbergensis, 

 spimtloides, oihonnce, blumi, muscicola ; Milnesium ; Macrobiotus 

 hufelandii, echinogenitus, coronifer, crenulatus, harmsivorthi, inter- 

 medius, areolatus, dispar, anibiguns, schaudinni, arcticus, zetlandicus, 

 angusti, annulatus, macronyx, tuberculatus, ornatus ; D. chilenense, 

 alpinum, scoticum, spitzbergense, angustatum. 



CONFINED TO ARCTIC AND SCOTLAND (AND ? FAROES). E. 

 islandicus, spinuloides ; M. crenulatus, zetlandiats, schaudinni, 

 D. spitzbergense, D. angiistatinn. 



COMMON TO ARCTIC AND SHETLAND (not yet known elsewhere 

 in Scotland). E. islandicus ; M. coronifer, crenulatus, harmsworthi. 



SCOTTISH ALPINE SPECIES. 



Almost any of the Scottish species may occur on mountain 

 tops, but there are a number which have only been found 

 in such situations, and others which are much commoner there 

 than elsewhere. These peculiarly alpine species are E. islandicus, 

 wendti, kerguelensis, gladiator (var. exarmatus, only on mountains), 

 oihonncR ; M. coronifer, crenulatus, harmsworthi, zetiandicus, 

 areolatus, montanus, orcadensis, D. alpinum. 



It will be observed that the majority of these (9 species) are 



