Collembola \:\ \ 



1 sotomurus palustris var. prasina Axelson, L905a, 1906. Wahlgren, L907 

 (Axelson) Liniianiemi, 1907, 1911, 1912. 



Yellowish green or pale yellowish, varying sometimes into yellowish red or 

 brownish; unicolorous, or with a trace of the median dorsal stripe. Length as 



great as 4. 5 mm. 



The specimens collected by the Expedition are uniform olive green in 

 colour, with paler furcula. In some specimens the median dorsal stripe is 

 represented, varying from a mere trace to a well-developed line, on head and 

 body. In some instances the posterior borders of the body segments arc edged 

 narrowly with blackish. Maximum length, 3 nun. 



These specimens, which I feel obliged to refer to the species palustris, differ 

 from typical European and North American examples of the species in having 

 more slender ungues, relatively shorter mucrones, unidentate unguiculi, and 

 particularly in lacking the characteristic long fringed sensory seta'. Further- 

 more, some of the largest of the curving body-seta' are feebly denticulate. In 

 other respects the specimens agree with palustris, as is evident from my f i li - 

 53-57. 



The variety prasina has been recorded from northern and middle Europe, 

 Bismarck archipelago, Siberia, Nova Zembla, and Ellesmere land. 



Many specimens: on ponds at Bernard harbour. Northwest Territories, 

 May 25/1916, June 16, 18, 25, July 9, 1915; under driftwood. Demarcation 

 point, Alaska, May 16, 1914. F. Johansen. 



Entomobrya comparata, n. sp. 



Plate 7, figs. 58-63. 



This form, like most other species of its genus, varies greatly in colouration. 

 Though the colour varieties intergrade, I have placed them in the following 

 three groups for the purposes of description:— 



(1) Pale lemon yellow, including antenna' and legs; furcula white. Eye- 

 Spots black; also basal antennal ring and a transverse band connecting the eye- 

 spots and the bases of the antennae. 



(2) Lemon yellow, with black antennal rings and interocular band, and 

 black median subcrescentic spot behind the eyes dig. 58). Anal segment black 

 dorsally. Antenna? purplish distally. Legs and furcula yellow. This is the 

 commonest form in the collect ion. 



(3) General colour brownish yellow, faintly and minutely mottled with 

 pigment. Segments bordered narrowly with black, as well as the posterior 

 border of the fourth abdominal segment, as in fig. 59. Anal and genital seg- 

 ments black dorsally. Fourth and fifth abdominal segments with a variable 

 amount of pigment vent rally. First antennal segment blackish apically; 

 remaining segments blackish. Femora and tibio-tarsi pigmented distally, and 

 the manubrium dorsally. 



Eyes 8 + 8, unequal (fig. 60). Antenna' a little more than twice a- long 

 as the head, with segments in relative lengths about as 1:10:9:12. Abdominal 

 segments in relative lengths as 13:19:14:40:6:4. Fourth abdominal segment 

 therefore about three times as long as the third. Unguis (fig. 61 with a pair of 

 lateral teeth and with inner margin tridentate in profile; all tine teeth being 

 actually doubled, however. Unguiculus extending a little beyond the middle 

 the unguis, broadly lanceolate, simple. One clavate tenenl hair. Dentes one 

 third longer than manubrium. Mucrones half as long as hind unguiculi, <>t the 

 usual form (fig. 62). Rami of tenaculum quadridentate ; corpus with one stoul 

 curving seta (fig. 63). General clothing of dense short curving fringed setae. 

 Dorsum of head and body with dense clavate fringed seta', less abundanl on the 

 last three abdominal segments. Antennas and legs densely setaceous. A leu 

 long fringed sensory seta' occur as usual. Length. I .7 mm. 



