466 



NEUROPTERA 



3. Osmylina : a group of delicate and elegant Insects of 

 small or moderate size, distinguished by the possession of three 

 simple eyes placed on the middle of the head just above the 

 antennae. A species of this group, Osmylus chrysops {maculatus 



of some authors), is an inhabitant 

 of Britain (Fig. 212) ; its larva is 

 to some extent amphibious. The 

 metamorphoses have been ob- 

 served by Dufour, Brauer, and 

 Hagen ; * it lurks under stones in 

 or close to the water, or in moss, 

 or on the stems of aquatic plants, 

 and pierces and empties small 

 Insects with its sucking-spears, 

 which are very elongate. The 

 young are hatched from the egg 

 in the autumn and hibernate 

 before becoming full grown ; 

 when this moment arrives the 

 larva spins a round cocoon of 

 silk mixed with sand. The pupa, 



^ a.i .uarva , _ 



B, side view of head of larva (after or nymph, in general appearance 



somewhat resembles the perfect 



Insect, except that it is shorter and has the short wing-pads 

 clinging close to the body. Dufour denied the existence of 

 abdominal spiracles in either larva or imago, but, according to 

 Hagen, they are certainly present in both. It would appear 

 that in the larva the alimentary canal is not open beyond the 

 chylific ventricle, and that its terminal section is modified to 

 form a spinning apparatus. 



Osmylus and its allies, including Sisyra, are now frequently 

 treated as a separate sub-family, Osmylides, equivalent to the 

 Chrysopides. In it is placed a very anomalous Insect Psectra 

 dispar of great rarity. The male has only two wings, the pos- 

 terior pair being the merest rudiments, though the female has the 

 four wings normally developed. Individuals of the male have been 

 found 2 in widely separated localities in the Palaearctic region 

 Somersetshire being one of them and also in North America. 



1 Linnaca entomologica, vi.i. 1852, p. 368, with plates. 

 2 See Albarda in Tijdschr. Ent. xvii. 1874, p. xvi. 



