112 



IIYDRACARINA 



La'Stly we shall list the watermites of Mount Elgon in equatorial Africa. Mt. Elgon is 

 the only tropical mountain of which the waterinite fauna has been studied. The following- 

 species have In^en found (Lundblad, 1927a) : 



List of the ll'alcrniitcs of Mt. Elgon {Above 1800 m.) 



1800-1900 m. 



Spcrchon fcnestratus 



1900-2400 m. 



Hygrobates loveni 

 Hygrobatnf^sis !ei ipalpis 

 Hxgrohatuiiicgapiis spatliulifertis 

 Megapus linearis 

 " tigandcnsis 



Hydrachna cldorctica 

 Hygrobates elgoncnsis 



Hygrobates laceratus 



Spcrchon elgoncnsis 



2400-3200 in. 



3200-3300 m. 



3300-4200 m. 



Megapus splendidus superbus 

 Octoniegapus viinutissiinus 

 A trad ides juciindiis 

 bryki 



Megapus splendidus 

 Atractidcs leniniiis 



Megapus affinis 

 Fiona angiilala 



Unfortunately we can by no means say that the watcrniitc fauna is well knuwu at higher 

 altitudes either in Sweden, Norway, or on Mt. Elgon. Probably, however, there are but few- 

 species to lie added to the Scandinavian fauna. Our highest mountains do not rise much 

 above 2000 meters, and they are always isolated summits. Our highest plateaus arc 

 hardly higher than 1000 m. Their area is very extended in Sweden, but is much split uj) 

 into smaller, isolated districts, the area of each measuring at the utmost some 10 square 

 kilometers. When following a certain level — for instance, that of 700 m. — from South to 

 North, we would find, however, that the number of species to be enumerated as living above 

 or at this level would diminish very rapidly. This indicates that the mites are not restricted 

 to a special elevation but that the temperature of the waters — or other circumstances, for 

 instance, the presence of food or hosts — determines their distribution. It is, therefore, of 

 little interest to state the vertical distribution of a species unless we at the same time report 

 the latitude at which the species was found. 



Consequently we find quite a numlier of watermites on Mt. Elgon even above 2000 

 meters, viz., 16 species, whilst there are no species in Sweden above 1100 meters. Undoubtedly 

 the fauna of Mt. Elgon, being at present superficially known, contains at least the same 

 number of undiscovered species as those already described. 



