26 COLLEMBOLA OF MINNESOTA 



ilies. The shape of the abdomen, and the fused condition of its 

 segments separate it from the family Entomobryidse to whicl. it 

 seems most closely related. The shortening- up of the body is 

 accompanied by a vertical position of the head, which gives way 

 in a few forms to an approximation to the primitive, horizontal 

 position. The ventral tube is always long and well-developed, 

 and has two long, exsertile filaments, glandular in appearance, 

 which can be thrust out or retracted at will. All are strong 

 jumpers and show a well-developed furcula and tenaculum. The 

 eyes show fewer cases of degeneration than in any other fam- 

 ily, the normal number of sixteen being almost always present. 



The family is represented in Minnesota by two genera, 

 which differ in the form of the antennae. Neither of the genera 

 possesses the post-antennal organ. 



a Ant. IV short, with whorls of hairs. The distal part of 

 Ant. Ill ringed. Genus Papirius, 26. 



b Ant. IV long, usually ringed. Ant. Ill not ringed. 



Genus Sminthurus, 27. 



Genus Papirius Lubbock 1862. 



This genus is represented by at least two species, both of 

 which are large and rather common. They are among the most 

 specialized of Collembola, inhabiting dark, shady places under 

 loose bark, under the caps of mushrooms, etc., where there is 

 a little moisture ; but I have never taken them on the surface of 

 water where so many other collembolans are found. In fact, 

 their furcula is not adapted for water leaping. There seems to 

 be little structural difference between our two species, but the 

 difference in color is so marked that one need have little dif- 

 ficulty in separating them. 



KEY TO THE GENUS PAPIRIUS. 



Color blue or purple marbled with pearly or lilac, sometimes 

 somewhat yellow. Ant. Ill with about five or six well de- 

 fined sub-segments, not including those fused into the large, 

 clubbed end. maculosus, 58. 



Color uniform over the body, usually purplish brown. Ant. 

 Ill with six or seven well-defined sub-segments besides 

 those fused into the clubbed end. unicolor, 59. 



