COLLEMBOLA OF MINNESOTA 99 



thirds as long as II, which equals III, IV is about as long as I 

 and II together. The genus has never been reported from North 

 America before, so far as I know ; and certainly the species never 

 has. They live socially, but must be rare in the localities where 

 I have collected, as I have taken them but once. They were found 

 under bark or under chips and boards in damp .situations near the 

 shore of Lake Pepin. 



Anurida tullbergi Schott. 



PI. XII, Figs. 8-9. 



1891. Anurida tullbergi. Schott, Nya Nordiska Coll. Ent. Tidsk. XII. 



p. 192. 

 1893. Anurida tullbergi. Schott, Plsearct. Coll. p. 91. PL VII, 17-18. 



1895. Anurida tullbergi. Renter, Finl. Coll. p. 33. 



1896. Anurida tullbergi. Coll. v. Hamburg, p. 164. PI. II, 23. 



"Post-antennal organs irregular. Elevations (tumores) in 

 each organ 24-28. Ocelli 10, 5 on each side of the head. Length. 

 2-2.5 mm." 



The claws are without teeth. The dark blue color of the in- 

 sect is laid on rather irregularly over a darker ground, giving 

 a somewhat netted appearance, the dark color far over-weighing 

 the light, which is more in evidence on the ventral side than on 

 the dorsal. 



Schott, from whom the substance of the above is taken, also 

 remarks that it lives like A. maritima Laboulb. except that he had 

 never taken A. maritima in fresh water, while A. tullbergi is 

 found on the surface of ponds. 



Evidently these species are very closely related, but the 

 shape of the post-antennal organ, as well as the much larger num- 

 ber of elevations composing the ring, will serve to separate it 

 from A. maritima which has but seven or eight, and these situated 

 in a circle. I have taken but two specimens of this species. 

 These were taken with a colony of Achorutes longispinus Tullb. 

 in a little pool at the edge of the wave-marks at Lake Pepin, 

 Minn. 



