the Biology of some British Neuroptera. 509 



in the swollen base of the maxilla. The salivary glands 

 furnish a secretion which probably serves for extra-oral 

 digestion and also is poisonous (vide Osmylus). A hungry 

 Chrysopa larva once pierced the skin between my fingers 

 and left a small white pimple, very irritating for two hours, 

 so that, together with noted effects on insect victims, I 

 think we may say that the secretion is decidedly poisonous. 



The nervous system of the larva consists of brain, sub- 

 oesophageal ganglion, three thoracic and eight abdominal 

 ganglia. In Coniopterygids (Plate XLIII, fig. 6) there is 

 marked concentration and reduction in size of abdominal 

 ganglia, there being only three in Conwentzia. Wing buds 

 and reproductive organs are first visible in the third-instar 

 larva. 



Pupa. — The anatomy varies with the age of the pupa. 

 Needless to say great changes take place in this short time. 

 A food reservoir to the oesophagus is present. The gizzard 

 is more distinct, as also are the developing reproductive 

 organs. 



Imago (Plate XXXIX, figs. 6-17). — The internal anatomy 

 of the imago differs from that of the larva mainly as follows. 

 There is a median dorsal food reservoir running back from 

 the oesophagus. This, on first emergence, is filled with air, 

 and is possibly filled up to increase the pressure within the 

 pupal skin previous to emergence. It is supplied by rami- 

 fications of two large tracheae from the second abdominal 

 spiracles. Often the food reservoir is laterally placed, and 

 one example has been seen in which a complete reservoir 

 was present on one side and a rudimentary one on the other. 

 There is a gizzard with longitudinal rows of chitinous teeth 

 within. A peritrophic membrane is, as before, always 

 present. The lumen of the hind-gut is now open for the 

 passage of excrement, but six of the eight Malpighian tubes 

 are still looped and loosely united distally to the hind-gut. 

 Malpighian tubes are colourless, except in imagines of 

 Osmylus and Sisyra. There are six globular rectal glands 

 which probably secrete a lubricant fluid, especially when the 

 larval excrement is passed. 



The salivary glands are of filamentous general type, but 

 may branch distally. They lead to the hypopharynx by 

 a short common duct, but posteriorly are doubled along the 

 sides of the oesophagus in the prothorax, being recurrent to 

 just behind the head. Also there is a thin walled gland, 

 often bilobed, to each maxilla. 



