METAZOA INSECTA. 449 



ing besides the antennae a short, thick abdomen and 

 large, gaily colored wings. 



A good example of differentiation in the second pair 

 of wings is found in Nemoptera ledereri. These organs are 

 extremely long and narrow, swelling out at their ends and 

 appearing like paddles. They doubtless aid the insect in 

 flying. 



As the development of Epicauta threw light upon the 

 life history not only of the Coleoptera but also of the 

 whole class of Insecta, so the development of Mantispa 

 illumines the life history of the Neuroptera and strengthens 

 our hypothesis in regard to the life history of insects in 

 general. 



Mantispa begins its life as a Thysanuriform larva (PI. 

 1141, fig. i, M. styriaca enlarged). This larva finds an 

 egg-case of a spider it maybe a Lycosa and making 

 a small opening, crawls into the sac. There, as the eggs 

 hatch, it devours the young spiders. The habitat within 

 the spider's egg-case causes marked changes in structure. 

 The body becomes caterpillar-like in form (fig. 2) and 

 the head small. The legs are reduced in size and in the 

 mature larva are useless vestiges, while the antennae are 

 shortened. The larva spins a cocoon within the egg-sac 

 and the pupa develops under the larval skin. The adult 

 No. 1142, having much the same habit as the praying 

 mantis (see Nos. 1012, 1013), has a similar structure. 

 The prothorax is greatly extended and the fore legs are 

 attached at the forward edge. These legs are long and 

 are adapted for seizing and holding prey, being held in 

 the same attitude as- in mantis. 



Order 12. MECOPTERA. 



The larvae of the Mecoptera, as represented by the type, 

 Panorpa communis Linn. (PL 1143, fig- I )> are caterpillar- 

 like in general aspect. In fact, all the Mecoptera larvae, 



