68 COLLEMBOLA OF MINNESOTA 



thick and stout, dentes unusually slender and whip-like, the fur- 

 cula just about reaching the ventral tube. Tullberg's figure 

 shows a minute inner tooth near the distal end of the large claw. 

 Schott's figure shows no such tooth. I have seen this in some 

 specimens. 



Isotoma viridis Bourl. 

 PI. IX, Figs. 5-7. 



1778. Podura viridis. Gmelin, Linnaeus Syst. Nat. Ed. XIII, p, 2910. 



1839. Isotoma viridis. Bourlet, Mem. cur. les. Podures. p. 401. 



1841. Desoria cylindrica. Nicolet, 1'Hist. des Podurelles. p. 60. 



1841. Desoria viatica. Nicolet, 1'Hist. des Podurelles. p. 61. 



1841. Desoria pallida. Nicolet, 1'Hist. des. Podurelles, p. 61. 



1841. Desoria ebriosa, Nicolet, 1'Hist. des Podurelles. p. 61. 



1841. Desoria annulata. Nicolet 1'Hist. des Podurelles. p. 61. 



1841. Desoria fusca. Nicolet, 1'Hist. des Podurelles. p. 62. 



1843. Podura viridis. Bourlet, Mem. sur les Podurelles. p. 24. 



1844. Isotoma viridis. Gervais, Hist. Nat. des Ins. Apt. III. p. 433. 

 1844. Heterotoma chlorata. Gervais, Hist. Nat. des Ins. Apt. III. p. 421. 

 1862. Isotoma lineata. Lubhock, Notes on the Thys. Pt. II, p. 597. 



1871. Isotoma palustris. Tullberg, Fort. ofv. Sv. Podur. p. 151. 



1872. Isotoma palustris. Tullberg, Sver. Podur. p. 46. 



1873. Isotoma anglicana. Lubbock, Monogr. Coll. and Thys. p. 171. 

 1873. Isotoma tricolor. Packard, Thys. of Essex Co., Mass. p. 34. 

 1890. Isotoma viridis. Uzel, Thys. Bohemian 



1893. Isotoma viridis. Schott, Palsearct. Coll. Plates V & VI. 



1895. Isotoma viridis. Reuter, Finl. Coll. 



1896. Isotoma viridis. Lie-Pettersen, Norges Coll. 



1896. Isotoma viridis. Schaffer, Coll. der Umgebung von Hamburg. 



Several color varieties of this species have been described, 

 but the specimens taken so far all appear to answer best 

 the description of the principal form, as given by Schott. The 

 color is rather a brownish yellow, darkening to an obscure pur- 

 ple along the back. There are no longitudinal markings. Legs 

 yellow, becoming purple in the darker specimens. Antennas 

 dark purple, often slightly paler at their base. Furcula pale. 

 A dark spot on the head. Ant. IV usually a little longer than 

 III and more plump than in I. palustris. Post-antennal organ 

 broader than in I. palustris, broadly oval. Abd. Ill slightly 

 longer than IV. Claws without tenent hairs. Superior claw 

 with one outer and two inner denticles, as in I. catena, fig. 15. 

 but without the minute apical tooth. Length, 2-4 mm. 



