COLEOPTERA . 427 



of earth, or if wood-borers in rude cocoons of fine chips and 

 dust, united by threads, or a viscid matter supplied by the in- 

 sect. None are known to be coarctate, though some Coccin- 

 ellae transform within the old larva skin, not rejecting it, as 

 usual in the group, while other pupaj are enclosed in the cases 

 in which the larv{\3 lived. In some Stajyliylinidce the pupa 

 shows a tendency to become obtected, the limbs being soldered 

 to the body as if it were enclosed in a common sheath. Gen- 

 erally, however, the antennae are folded on each side of the 

 clypeus, and the mandibles, maxillai and labial palpi appear as 

 elongated papillae. The wing-pads being small, are shaped 

 like those of the adult Meloe, and are laid upon the posterior 

 femora, thus exposing the meso- and metathorax to view. 

 The tarsal joints lie parallel on each side of the middle line 

 of the body, the hinder pair not reaching to the tips of the 

 abdomen, which ends in a pair of acute prolonged forked in- 

 curved horny hooks, which must aid the pupa in working its 

 way to the surface when about to transform into the beetle. 



The number of living species is between 60,000 and 80,000, 

 and over 8,000 species are known to inhabit the United States. 

 There are about 1,000 fossil species known. They are found 

 as low down as the Coal Formation, though more abundant in 

 the Tertiary deposits and especially the Amber of Prussia. 



Coleoptera have always been the favorites of entomologists. 

 They have been studied, when in their perfect state, more than 

 any other insects, but owing to the difficulty of finding their 

 larvae, and carrying them through their successive stages of 

 growth, the early stages of comparatively few species are 

 known. 



The most productive places for the occurrence of beetles are 

 alluvial loams covered with woods, or with rank vegetation, 

 where at the roots of plants or upon their flowers, under leaves, 

 logs and stones, under the bark of decaying trees, and in 

 ditches and by the banks of streams, the species occur in the 

 greatest numbers. Grass lauds, mosses and fungi, the surfaces 

 of trees and dead animals, bones, chips, pieces of board and 

 excrement, should be searched diligently. Many are thrown 

 ashore in sea-wrack, or occur under the debris of freshets on 

 river banks. Many Carabidoi run on sandy shores. Very 



