66 LINNEAN SYSTEM. 



water fishes, as are also the flies : they are more numerous in running 

 than in standing waters. 



Genus 56. Phryganea. 

 Moufh with a horny, short, arched, acute mandiltle, without teetli ; and 

 a memhranaceous maxilla: pa/pi. I'uur: sie/nuiald three: antennee se- 

 taceous, longer than the thorax: wings incumbent; the hinder ones 

 folded. (P/. r./if.S.) 



Genus 57. IIemerobius. 

 Mouth with a straight horny mandible: a cylindrical, .straight, cleft 

 vHtxUla: Up stretched forward and entire: four jirojecting, unequal, 

 filiform ;K//y>/ : no steinniata : yawgs deflected, not folded : atitenna se- 

 taceous, projecting, and longer than the thorax, which is convex. 

 The species of this genus in all their stages feed upon small insects, 

 especially the Aphides; their larvai have six feet; in most species they 

 are oval and hairy; the pupa; are inactive, and inclosed in a case. The 

 eggs are deposited on leaves in the midst of Aphides; they are sup- 

 ported on small pedicles and set in the form of bunches. The larvee at- 

 tain their growth in fifteen or sixteen days, and the yupa incompleta re- 

 mains for three weeks before the fly comes forth. 

 Sp. 1. II. Chri/sops. {PL 7. fig. 4.) Chrysops maculata, Leuch. 



Genus 58. Panorpa. 



Movth stretched out info a cylindrical horny rostrum : the 7nandihle\s 

 without teeth: viaxUlce bifid at the apex: /;)) elongated, and covering 

 the whole mouth : palpi four, nearly equal : stemmatu three : antennae 

 filiibrm : the lail of the male armed with a chela, that of the female 

 unarmed. 



Sp. 1. P. communis. (Fl. 7. Jig. 5. a. chela 7nagnificd.) 



Genus 59. Rapiiidia. 

 Mouth with an arched, dentated, horny tmudibk : a cylindrical, obtuse 

 iiorny maxilla: a rounded, entire, and horny lip: palpi fom-, very 

 short, nearly equal, and filiform : stemmata three ; icings deflected : un- 

 tennm filiform, of the length of the thorax; elongated before, and 

 cylindrical; tail of the female with a lax recurved seta. (P/. I.f'g. 6.) 



Order V. HYMENOPTERA. 



Wings four, membranaceous : mouth with maxillze, and some of them 

 likewise a tongue. Between the large eyes they h?,ve generally three 

 j-tcnnnata. At the extremity of the abdomen the females of several of 

 the genera have an aculeus or sting, that lies concealed within the ab- 

 domen, which is used as a weapon, and instils into the wound an acid 

 poison : those which want the sting, are furnished with an oviduct, tliai 



