168 ISOTOMA. 



The eggs are round and yellow, turning to purplish 

 red. 



The young when.first hatched resemble their parents 

 in general form, but are reddish in colour. 



Sweden, Switzerland, France, Holland, Great Britain. 



Found in the winter months. 



Nicolet's D. ehriosa is founded on a pale specimen 

 which was about to lay eggs. I have met with several 

 individuals answering to his description, and have found 

 that the colour of the abdomen was due to the yellow 

 eggs contained in it. After they were laid, the posterior 

 segments were of the same colour as the others. In 

 darker specimens the skin is more opaque, and the 

 eggs, therefore, do not affect the colour. 



Isotoma viatica. 



Podv/ra viatica, Linn. Faun. Suec. 



La podure noire terrestre, Geoff. Ins. Env. Paris. 



Podura viatica, Linn. Fauna. Suec. 



— — Boisd. and Lacord. Faun. Ent. Env. Paris. 

 Besoria — Nicolet. Mem. Soc. Helv., 1842. 



Podura — Lucas. His. Nat. Crus. Arach. & Myr. 



— — Gervais. His. Ins. Apteres, vol. iii. 

 Isotoma — Nicoiet. Ann. Soc. Ent. France, 1847. 



Plate XXXYI. 



Bluish-black ; eyes on intensely dark patches ; body 

 clothed with short hairs ; segments of the antennae 

 subequal ; body cylindrical ; spring short, not reaching 

 to the ventral tube. 



This species may at once be distinguished from the 

 preceding by the darkness of the legs. 



Length "OS of an inch. 



January to April. 



I have not met with this species often, but when 

 found it generally occurs in abundance. 



