The Simplest Insects 
61 
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- d 
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 Fig. 90.— Young and adult of Ca 
podea staphylinus (from California), 
the simplest living insect. (Natural 
size indicated by line.) 
than Campodea, being about one-half inch 
long, and is readily recognized by its caudal 
forceps. Like Campodea its body is white and soft. 
The Lepismidse 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- 
fifths of an inch long. The three long caudal appen- 
ensis , from Califor- dages, characteristic of the genus, are conspicuous. It 
nia. (Eight times nat- f eec j s chiefly on sweet or starchy materials, sometimes 
ural size.) _ . ; . ...... . . 
doing much damage m libraries, where it attacks the 
bindings. It attacks starched clothing, eats the paste off the wall-paper, 
