420 



COLEOPTERA. 



,:l 



COLEOPTERA. 



In the highest suborder of this series, the Coleoptera, we 

 find the most complete metamorphosis and the greatest speci- 

 alization of parts, with 

 a more complete con- 

 centration of them to- 

 wards the head than in 

 the lower suborders. 

 They are at once rec- 

 ognized by the elj'tra, 

 or thickened hornj- fore 

 wings, which are not 

 actively used in flight 

 (the hind wings being 

 especially adapted for 

 that purpose) , while 

 they cover and encase 

 ■nj the two posterior seg- 

 ments of the thorax 

 and the abdomen. The 

 pro thoracic ring is 

 gi'eatly enlarged, often 

 excavated in front to re- 

 ceive the head. These 

 characters are very per- 

 sistent ; there ai'e few 

 aberrant forms and the 

 suborder is remarkably 

 homogeneous and easily 

 limited. 



The head is free from 

 the thorax, but less so 

 than in the preceding suborders ; it is scarcely narrowed behind, 

 and its position is usually horizontal. The eyes are usually 



Fig. 345, under sui-face of Harpalus caliginosus. (iVfter Leconte.) o, licnila; 

 f«, paraglossas; c, supports of labial palpi; rf, labial palpus; e, mentum;/. inner 

 lobe of maxilla; g, outer lobe of maxilla; ft, maxiUary palpus; t, mandible; A-, 



