8 GUSTAF EISEN, ON THE AECTIC OLIGOCHJETA. 



Segmentum anale prseanali longius. 



Setse ubique binse, dorsuales magis quam ventrales distantes, ubique tamen binse 

 approximata?. 



Longitudo circiter 40 — 60 m. m. 



Habitat: Collected during the expedition in Norway on the islands of Lofodden 

 s:a Hindön, Karlsö, and on Lavangsfjell. The specimens were generally larger than 

 our Swedish ones, but more resembling those I have collected in North America. The 

 examination of a larger number of specimens to which I have recently had access 

 make me believe that the species A. arborea and tenuis described by me are only va- 

 rieties of the same form, for which the name of A. tenuis may perhaps be kept to the 

 greatest advantage. 



Some of the specimens from Hindön also show a swelling on the 27 th segment, 

 which might be mistaken for a tuberculum pubertatis and which also indicates the 

 relation to the preceding species A. subrubicunda, but with which it never occurs. 



Deiidrobteiia Eisen. 



1874. Öfversigt af K. Sv. Vet. Akad. Förhandl. 1873. N:o 8. p. 53. 

 Setae, in utroque segmenta octo, distantes. 



Dendrobaena Boeckii Eisen 1874. 



Syn.: 1871. Lumbricus puter Eisen, Öfversigt af K. Sv. Vet. Akad. Förhandl. 

 1870. p. 959. 



1874. D. Boeckii Eisen, Öfversigt af K. Sv. Vet. Akad. Förhandl. 1873. p. 53. 



Tubercula pubertatis in segmentis 30, 31, 32, in utroque latere cinguli. 



Habitat: found by the expedition both in Norway and in Siberia. In the former 

 countiy, in which it is also of a more southern distribution, it was taken on Lavangs- 

 fjell and on the islands of Lofodden. In Siberia again at Surgatskoj, lat. 62° 50', and 

 between Tomsk and Krasnojarsk, lat. 55°. In Novaja Semlia on »Lundströms moun- 

 tain» at Matotschkin Sharr (lat. 73° 20')) also at Besimanaja bay. 



»Lundströms mountain» is the northern most point at which any Lumbricid has 

 hitherto been found, and according to our present knowledge of the distribution of the 

 Lumbrici it can be safely stated that of all their species Dendrobcena Boeckii goes farthest 

 into the arctic region. 



The following table will give a better view of the geographical distribution of 

 the above species than a mere enumeration of the localities. 



