MICROSCOPIC OBJECTS. 68 



Fig. 135. Larva of the Ant-lion (Myrmeleon formicarius) , 

 x 4. Order Neuroptera. 



The chief characteristics of the order are: that the perfect 

 insects have four large membranous wings, of which the 

 Dragonfly is an example ; and that the larvae are nearly all 

 furnished with very strong mandibles, in the case of some of 

 the Dragonflies called the mask (see fig. 136). Most of the 

 larvae of this order live in water ; but the larva of the Ant-lion, 

 with others, forms an exception. With its strong legs and 

 mandibles it makes for itself a funnel of loose sand or soil, 

 at the bottom of which it lies concealed, waiting for its prey. 

 This larva is also furnished with very strong mandibles. 



It is best mounted in balsam. The perfect insect very 

 much resembles the small blue Dragonfly (Agrion puella) 

 that is so very commonly met with at the margins of our 

 rivers and ponds. 



Fig. 136. Head of Larva of the Long-bodied Dragonfly 

 (Agrion virgo), x 12. 



The larvse of the Dragonflies are furnished with a kind of 

 moveable mask, which is armed with very strong pincers. 

 This mask is concealed under the head of the insect, and 

 when called into action it is darted forward to nearly the 

 entire length of the body. After its prey has been caught, 

 it is brought by this peculiar apparatus into the reach of the 

 mouth. The respiration of the larvae of the Dragonflies is 

 also remarkable ; they take in a certain amount of water, 

 and, after the oxygen has been exhausted, discharge the same 

 suddenly (by this mechanism the larva is also propelled in 

 the water) . 



The larvae may be mounted in a cell in strong acetic acid, 

 or dried and mounted in balsam. 



