COLEOPTEROUS INSECTS. 187 



iarva forms for its protection an oval cocoon, con- 

 structed of earth and the gnawed fragments of other 

 materials, agglutinated by a viscous secretion which 

 exudes from its body. 



The lamellicorn insects may be regarded as con- 

 stituting two great groups or tribes, corresponding 

 to the two comprehensive genera of Linnaeus, Sca- 

 rabaeus and Lucanus. In the former the antennae 

 terminate in a foliated mass, generally capable of 

 being alternately closed or expanded ; but it is 

 sometimes composed of joints that fit into each other, 

 either in a globular form, or in the shape of a re- 

 versed cone : the mandibles are nearly alike in both 

 sexes, and the males are frequently distinguished 

 by horns or prominences on the head and thorax. 



The first generic group among the SCARAB^ID^E, 

 which requires to be noticed, has been named 



ATEUCHUS. 



The term is probably derived from the Greek 

 privative a, and nu^f, a weapon or implement of 

 war, in allusion to the head being without horns, 

 contrary to what is observed in most of the allied 

 genera. The antennae consist of nine joints, the 

 three next the apex forming a foliaceous knob. The 

 body is somewhat rounded, and usually rather de- 

 pressed, and there is scarcely any appreciable mark 

 of distinction in the external appearance of the two 

 sexes. The maxillae terminate in a membranous 



