168 ZOOLOGY. 



Agrion {2)1. TO, fig. 73), Caleptenjx {fig. 74), Libellula {fig. 75), and 

 ^scJina {fig. 76). They have the body slender, the wings large and 

 reticulated, the head, and paiiicularly the eyes, large, the mouth well 

 developed, and they are of predaceous hal)its in the larva and imago state. 

 In the latter the feet are slender, adapted for standing rather than for loco- 

 motion, and they resemble the swallow in passing most of their time and 

 taking their prey in the air. They are sometimes found in forests, but 

 generally along water courses. The larviis are acpiatic, and the eggs are 

 deposited upon the water by the female, who allows the tip of her abdomen 

 to touch the surftice at the time of exclusion. 



Among the Myrmeleonidce., the genus Myrmeleon {M. libelluloides.^ ^il. 

 1^.,fig. (50; M.formicarii(s^fig.Qla) is remarkable for the habits of the 

 larva {fig. 61 i), which forms a conical depression in the ground where the 

 earth is dry and pulverulent (the dust of decayed wood being preferred in 

 the United States). Beneath the bottom of this cavity the larva lies either 

 entirely covered, or with the mandibles exposed. When an ant or other 

 insect wanders across one of these pits, it slides down the sloping side, and 

 the particles which roll to the bottom indicate the presence of an object, 

 upon which the larva, by upward jerks of the head, tosses up a little shower 

 of dust, which, falling on and around the intruder, carries it within reach 

 of its wily enemy. In Virginia this insect is called a Jioodlhug., and the 

 repetition of this word over its opening in a half singing tone, is said to cause 

 the bug to come from beneath its cover, although it is probable that the 

 breath of the operator is the true cause. Ascalaphus {A. harhanis., pi. 79, 

 fig. 59) is remarkable for having the antennae knobbed, as in some of the 

 butterflies. 



In the family Hemerohiidce^ the larvje of Clirysopa {p>l. 79, figs. 63, 

 64) are found upon plants, where they feed upon Aphides. Drepanepteryx 

 fhalmwides is remarkable for its resemblance to some of the small 

 butterflies. 



The remarkable American genus, Corydalis belongs to the Sialidce. 

 The insects of this genus are of a large size, the mandibles of the male 

 resembling the horns of an ox. The larva is aquatic and predaceous. 



In the PanorpidcB {pi. 'Id., fig. 58), the head is produced into a rostrum. 

 Panorpa {pi. 'id, fig. 58), Bittacus {fig. 57). 



In the Raphidiidce {Paphidia.ipl. 19, fig. 55), the prothorax is long and 

 the head flattened, presenting a distant resemblance to a snake. 



The Mantispidm {Mantispa, pi. 79, fig. 54) have the body somewhat as 

 in Panorpa, and the anterior feet are raptorial, resembling those of Mantis, 

 with which they were classed by some of the earlier entomologists. 



The PhryganeidcB {pi. 79, figs. 65-69) constitute Kirby's order 

 Trie hop f era, which is adopted by a considerable number of entomologists. 

 The body is soft, the wings are membranous, the posterior pair the larger, 

 and generally folded longitudinally, the anterior generally pilose (whence 

 the name of the order), and the antennie setaceous. The mouth is man- 

 dibulate, but is unfitted for mastication, and the mandibles are obsolete. 

 The pupa is inactive, and the larvne are aquatic, and generally construct 

 372 



