20 REPORT OF NEW JERSEY STATE MUSEUM. 



scale insects. These creatures are able to puncture tissue and to 

 suck the juices of animals or plants as the case may be. 



The Parasitica contains those forms without wings, adapted to 

 live among the hair, on the blood o>f certain vertebrates, and here 

 the lancets are retractile into the head, the beak being lost or 

 modified into 1 a short snout with or without anchor hooks or 

 processes. 



The order Hoiiwptcra, or Hemiptera-Homoptera, contains the 

 plant lice, scale insects, leaf-hoppers, mealy bugs, etc., hence is, 

 in its entirety, injurious to the agriculturist. The head is here 

 closely applied to the thorax, the beak is directed backward and 

 issues underneath the head so far that, in many cases, it seems 

 to' come out between the front legs. . In the scale insects the beak 

 is lost in the female, and in the males the mouth structures are 

 partially or altogether lost. When wings are present they are 

 uniform in texture throughout, but there is often a difference in 

 the texture of the two pairs. 



The order Heteroptera or Heuiiptera-Heteroptera marks the 

 extreme of the development in the Rhyngota, and here the mouth 

 structures are more free, the beak often from the front of the 

 head so that it may be directed straight forward, the forewings 

 thickened and leathery or chitinous at base, thin and mem- 

 braneous at tip, usually divided into well-marked regions. None 

 of the Rhyngota have a completed metamorphosis and altogether 

 this branch, with sucking mouth parts in all stages, remained a 

 limited and inferior one. 



The branch in Which mandibles were developed found a much 

 greater range of food-getting possibilities and split up into a 

 much greater number of divisions. 



With the development of wings, the thoracic segments which 

 bear the organs of locomotion became modified. At first the 

 three segments were similar to each other, and one series retained 

 this peculiarity, all the rings being of practically equal import- 

 ance. All these are loose-jointed frail forms with large, trans- 

 parent wings. A departure was made when the second and 

 third segments, which bear the wings, became united for more 

 compact muscular attachments, and the first segment or prothorax 



