COLLEMBOLA OF MINNESOTA 71 



1788. Podura palustris. Gmelin, Linnaeus Syst. Nat. Ed. XIII. Prt. VI. 



p. 291 1. 

 1842. Podura palustris. Bourlet, Mem. Soc. Roy. Douai. 



1842. Aetheocerus aquaticus. Bourlet, Mem. Soc. Roy. Douai. 



1843. Podura palustris. Bourlet, Mem. sur les Podurelles. p. 29. 

 1857. Podura psi. Herklots, Notices Entomologiques. 



1872. Isotoma palustris. Tullberg, Sver. Podur. p. 45. PI. IX, 1-8. 



1873. Isotoma palustris. Lubbock, Monogr. Coll. and Thys. p. 169. 

 1890. Isotoma palustris. Uzel, Thys. Bohemise. p. 62. 



1893. Isotoma palustris. Schott, Palsearct. Coll. p. 63. PI. V, 8, and VI, 



3-5- 



1895. Isotoma palustris. Renter, Finl. Coll. p. 26. 



1896. Isotoma palustris. Lie-Pettersen, Norges Coll. p. 16. 



1896. Isotoma palustris. Schafifer, Coll. der Umgebung von Hamburg, 

 p. 186. 



Schott gives about the best diagnosis of this variety : "Yel- 

 low with a median black dorsal line. On the sides of the apical 

 segments of the abdomen, scattered fuscous spots which some- 

 times from dark longitudinal bands. Length, 2.5 to 3 mm." 



Ground color a dirty yellow with a dark blue median band. 

 The sides are usually a dirty purple, sometimes forming well- 

 defined lateral bands, sometimes shading ofT lighter to the dor- 

 sal yellow. Two characteristic, dark purple spots appear on 

 the sides of the last abdominal segment. Often the furcula, un- 

 der side of body and of head, mouth-parts, lower sides of femurs 

 and of tibias, and basal part of ventral tube are of a bright 

 green. Distal part of ventral tube yellow. Dorsal side of femur 

 purple, cheeks washed with purple, antennae purple, also purple 

 around their base. Post-antennal organ oval. A dorsal purple 

 spot on the head. Older specimens are darker than young and 

 usually show more green. Ant. IV is more slender than III, 

 and seldom quite as long. The whole antenna is covered with 

 short, stout hairs. Indeed, the entire body is set thickly with 

 short, dark brown hairs of uniform length, in this differing from 

 I. viridis which has some longer hairs as well. The mucrones 

 is four-toothed. The claws are much the same as in I. caerul- 

 eatra, but lack the inner tooth on the superior claw. Sometimes 

 the claws of the second and third pairs show a small outer tooth 

 on the superior claw as in I. viridis, but less noticeable than in 

 that species. No tenent hairs present. Some authors give the 

 length as 4.5 mm., but I have never taken any that measured 



