252 



MANUAL OF ZOOLOGY. 



The order Coleoptera includes all those Insects known com- 

 monly as " Beetles," comprising an enormous number of species 

 and genera. 



The larvae of the 

 Coleoptera are vermiform 

 grubs, with masticatory 

 mouths, usually three 

 pairs of thoracic legs, 

 and often anal pro-legs. 

 DISTRIBUTION OF IN- 

 SECTA IN TIME. The 

 earliest known insects 

 have been discovered in 

 the Devonian Rocks of 

 America, and consist of 

 the remains of Nenrop- 

 tera. Others, as might 

 have been anticipated, 

 have been found in the 



Rose-chafer (Cetonia Coal-meaSUrCS. Ill the 



vine-Weevil (Curcuiio Secondary Rocks re- 

 mains of Insects have 

 been found abundantly in certain beds of the Oolitic and Liassic 

 formations. In some Tertiary strata Lepidoptera and other in- 

 sects have been found in a good state of preservation. Amber, 

 which is a fossil resin, has long been known to contain many 

 insects in its interior (in certain specimens); and all of these 

 appear to belong to extinct species, though amber, geologically 

 speaking, is not an ancient product. 



Fig. 92. Coleo 

 aurata) and 

 sulcatus). 



