b GUSTAF EISEN, ON THE ARCTIC OLIGOCHiETA. 



Segmenta circiter 130, contracta. 



Longitudo specirainis in vino asservati circiter 60 m. m. 



Habitat: Collected by the expedition in a few places in Siberia: Werschininskoj 

 (lat. 68° 45') and Worogowa Selö (60° 50'). Previously known to inhabit Norway and 

 Sweden, Germany and N. America. 



Allolob ophor a Nordenskiöldii n. sp. 



Species Allolob. foetidae valde affinis. 



Corpus cylindricurn, elongatum, crassum, postice depressum. 



Lobus cephalicus parvus, postice tenuis, dimidiam partem segm. buccalis occu- 

 pans, ssepissime infra sulco longitudinali; supra sulco singulo transverso. 

 Oingulum non protninens, e septem segmentis saspe confectum. 

 Tubercula pubertatis in utroque latere cinguli tria, segmenta 28, 29, 30 occupantia. 

 Setse ubique binte valde approximatas. 

 Segmenta 80 — 125. 



Longitudo maxima circiter 80 — 150 m. m. 



Macula pallida in latere superiore segmentorum anteriorum 8, 9, 10. 

 Setarum pars anterior lineis curvatis minutissimis incisa. 

 Habitat: Siberia in several locaiities: 

 Waigatsch: lat. 69° 45' Cap Grebenij. 

 Jenissej : lat. 71° 55' Schaitanskoj. 



» » 70° 39' Briochowskij islands. 



)> « 70° 5' Sapotschnoi island. 



>' » 69° 15' Dudino. 



» » 68° 45' South of Werschininskoj. 



» » 65° 45' » » Troitskoj. 



» » 64° 25' Baklanowskij. 



» » 63° 30' Aninskoj. 



» » 60° 50' Worogowa Selö. 



The largest specimens, collected in the most southern locality, at Worogowa Selö, 

 attain a size not equalled by any other North-European Lumbricid except L. terr estris. 

 From the comrnon Allolobophora foetida, its nearest ally, the present form is 

 distinguished principally by two characteristics, viz.: 



1) by having tubercula pubertatis on the 28 th , 29 th and 30 th segments, when Allo- 

 lob. foetida has the same tubercles on the 27 th , 28 th and 29 tK . 



2) by having the frontpart of the setse marked or engraved with minute curves. 

 In Allolob. foetida the same place is dotted with small circular or oblong hollows. See 

 Pl. VIII, figures 14 and 15, the former representing Allolob. Nordenskiöldii, the låter 

 A. foetida. 



Also the colour of the two species seems to be somewhat different. The .colour 

 of A. foetida is too well known to be described here, and it may suffice to mention 

 that, to judge from alcoholic specimens, the bright yellow bands of that species do not 

 exist in A. Nordenskiöldi. 



