ORDER STREPSIPTERA. 



185 



714. This is probably the place in which the small Order 

 STREPSIPTERA should be introduced ; although the insects com- 

 posing it depart so widely from the general type, that it is 

 difficult to say to what orders they are most nearly allied. They 

 are few in number ; and are parasitic in their larva state upon 

 other insects, especially the solitary Bees belonging to the 

 family Andrsenidae. The name of the Order, which means 

 " twisted wings," has reference to certain curious appendages, 

 that look as if they had 

 been twisted, which are 

 seen in front of the 

 wings ; these appendages 

 are attached to the se- 

 cond segment of the 

 thorax, whilst the wings 

 (of which there is only 

 one pair) proceed from 

 the third; hence they 

 are to be regarded as the 

 altered rudiments of the 

 anterior pair of wings, in 

 the same manner as the 

 balancers of the Diptera 

 are to be considered as 

 the rudiments of the 

 posterior ( 724). The 

 most remarkable feature 



in the organisation of these insects, is the absence of any opening 

 at the mouth ; although it is furnished with appendages in some 

 degree resembling those of the Lepidoptera. The eyes are large 

 and prominent, being mounted on footstalks as in many Crus- 

 tacea. The antennas are of singular form, being usually furnished 

 with an internal branch or projection nearly as long as the 

 antennae itself. The wings are large, and folded in a fan-like 

 manner ; when in motion they make a buzzing sound, which is 

 considerable in proportion to the size of the animal. The third 

 segment of the thorax, to which they are attached, is developed 



411. A, Stylops Dalii, nat. size; B, magni- 

 fied ; c, Andrena, with the heads of two of its 

 larvae exserted between the abdominal rings, a , 

 D, larva extracted and magnified. 



