COLEOPTERA. 99 



posed of stiff prickles, around the thin edges of the body, and a 

 long forked tail. This fork serves to hold the excrement when 

 voided ; and a mass of it half as large as the body of the insect is 

 often thus accumulated. The tail, with the loaded fork, is turned 

 over the back, and thus protects the insect from the sun, and 

 probably also from its enemies. The first broods of larvae arrive 

 at their growth and change to pupae early in July, fixing them- 

 selves firmly by the hinder part of their bodies to the leaves, 

 when this change is about to take place. The pupa remains fast- 

 ened to the cast-skin of the larva. It is broad oval, fringed, at 

 the sides, and around the forepart of the broad thorax, with large 

 prickles. Soon afterwards the beetles come forth, and lay their 

 eggs for a second brood of grubs, which, in turn, are changed to 

 beetles in the course of the autumn. In June 1824, the late Mr. 

 John Lowell sent me specimens of this little beetle, which he 

 found to be injurious to the sweet potato-vine, by eating large 

 holes through the leaves. This beetle is very broad oval in 

 shape, and about one fifth of an inch in length. When living it 

 has the power of changing its hues, at one time appearing only of 

 a dull yellow color, and at other times shining with the splendor 

 of polished brass or gold, tinged sometimes also with the variable 

 tints of pearl. The body of the insect is blackish beneath, and 

 the legs are dull yellow. It loses its brilliancy after death. The 

 wing-covers, the parts which exhibit the change of color, are 

 lined beneath with an orange-colored paint, which seems to be 

 filled with little vessels ; and these are probably the source of the 

 changeable brilliancy of the insect. 



The Chrysomelians (Crysomelad^) compose an extensive 

 tribe of leaf-eating beetles, formerly included in the old genus 

 Chrysomela. The meaning of this word is golden beetle, and 

 many of the insects, to which it was applied by Linnaeus, are of 

 brilliant and metallic colors. They differ, however, so much in 

 their essential characters, their forms, and their habits, that they 

 are now very properly distributed into four separate groups or 

 famihes. The first of these, called Galerucad^, or Galeru- 

 cians, consists mostly of dull-colored beetles ; having an oblong 

 oval, slightly convex body ; a short, and rather narrow, and un- 

 even thorax ; slender antennae, more than half the length of the 



