The Simplest Insects 



61 



podea staphylinus (from California), 

 the simplest living insect. (Natural 

 size indicated by line.) 



is a striking proof that Nature does not inevitably crush out all of her 

 first trials in favor of her later results! 



The Campodeidae contain another 

 genus, Nicoletia (Fig. 91), one species of 

 which, N. texensis, has been found in Cali- 

 fornia and Texas, and which may be dis- 

 tinguished from Campodea by its posses- 

 sion of three caudal appendages instead 

 of two as in the latter form. 



The Japygidae include but a single 

 genus, Japyx, represented in this country 

 by two described species and several as yet 

 undescribed forms found at Stanford Uni- 

 versity. Japyx subterraneus is a species 

 first found under stones at the mouth of 

 a small grotto near the Mammoth Cave 



(Kentucky). Japyx (Fig. 92) is larger FI G. 90. Young and adult of Cam- 

 than Campodea, being about one-half inch 

 long, and is readily recognized by its caudal 

 forceps. lake Campodea its body is white and soft. 



The Lepismidae include the familiar household fish- 

 moths and a number of similar forms which live under 

 stones and logs in soft soil at the bases of tree-trunks, 

 under dead leaves in woods, and sometimes on the damp 

 sand of seashores. Three genera of this family occur 

 in North America, which may be distinguished as 

 follows : 



Caudal appendages short; prothorax very wide and body 



behind it tapering rapidly LEPISMINA. 



Caudal appendages long; body elongate and tapering 

 gradually backward. 



Eyes large and close together MACHILIS. 



Eyes small and far apart LEPISMA. 



Lepisma is best known by the species L. saccharina 

 (Fig. 86), which is the silverfish or fish-moth of the 

 house. It is silvery white, with a yellowish tinge on 

 the antennae and legs, and is from one-third to two- 



FIG. gi.-Nicoletia tex- fifths f an inch . l n g' The three lon g Caudal a PP en - 

 ensis, from Califor- dages, characteristic of the genus, are conspicuous. It 



urai sle g ) httimeSnat ~ feeds chiefly on sweet or starch y mat enals, sometimes 



doing much damage in libraries, where it attacks the 



bindings. It attacks starched clothing, eats the paste off the wall-paper, 



