ON ARCTIC TARDIGRADA. 679 



there are undoubtedly many more to be discovered, as various eggs are known which 

 cannot be referred to any of the described species. 



In this paper the Arctic Region is restricted to the area within the Arctic Circle, 

 following Richters' practice in " Arktische Tardigraden," so that our results may be 

 easily comparable. Climatically, Iceland, S. Greenland, and parts of Northern Europe 

 outside the Arctic Circle should, no doubt, be treated along with the region within 

 the Arctic Circle. 



The term Antarctic Region in the following table has a laxer meaning, and includes 

 all the lands south of the great continents for which any records are available. This 

 treatment was necessitated by the different climate of the southern Polar Region, 

 within which, defined as bounded by the Polar Circle, only one Tardigrade is known. 



In the appended table of all the Arctic species known, the aim is to give a 

 general view of the distribution of each species in Arctic lands and over the world. 

 These records of distribution do not profess to be nearly complete, as I have failed 

 to have access to several works containing records. 



For the world distribution I am mainly indebted to the table in Richters' 

 " Arktische Tardigraden," but in order to give as comprehensive a view as I could, 

 I have added many notes of Asian, African, and American species not yet published. 



In the table the records are given under eleven headings, five of which give the principal 

 Arctic lands for which we have records — the others being Scotland, Central Europe, 

 Asia, Africa, America, and the Antarctic Region. 



LITERATURE CITED. 



(1) Doyere, Ann. Sc. Nat, Taris, Ser. II. T. 14, 1840. 



(2) Ehbenberg, Mikrogeulogie, 1854; Atlas, PI. 35b. 



(3) Greeff, Mas. Schnltze's Arch. f. Milcr. Anat., Bd. ii., 1866. 



(4) Murray, J., "Tardigrada of the Scottish Lochs," Trans. Roy. Soc. Edin., vol. xli., 1905. 



(5) „ "Tardigrada of the Forth Valley," Ann. Scot. Nat. Hist., 1905. 



(6) ,, "Scottish Alpine Tardigrada," Ami. Scot. Nat. Hist., 1906. 



(7) ,, "Encystment of Macrobiotu*, " Zoologist, 1907, p. 4. 



(8) „ "Scottish Tardigrada," Trans. Roy. Soc. Edin., vol. xlv., 1907. 



(9) Plate, L. H., " Naturgeschichte der Tardigraden," Zool. Jahrb., Bd. iii., Morph. AM., 1888. 



(10) Richters, F., Ber.Senckenbg. Natf. Gps., 1900, p. 40. 



(11) „ "Nordische Tardigraden," Zool. Ang., Bd. xxvii., 1903. 



(12) „ "Arktische Tardigraden," Fauna Arctica, Bd. iii., 1904. 



(13) Schaudinn, Fauna Arctica, Bd. ii., 1901. 



(14) Schultze, C. A. S., "Macrobiotus hufelandii," Oken's Ms, 1834, p. 708. 



(15) Scourfield, D. J., "Non-Marine Fauna of Spitsbergen," Proc. Zool. Soc. London, 1897. 



