HYDEOrSYCHlD.E. — HYDROI'SYCHE. I7I 



or rounded; transverse nervures few in number, irregularly dispersed, the 

 middle of the costa without one : posterior wings ovate, with a trifid 

 nervure in the centre : legs moderately stout : anterior tihlce with a pair of 

 spurs at the apex, intermediate and posterior with a pair of long ones at the 

 tip, the former with a second pair above the middle, and the latter with a 

 pair much below the middle : intermediate tibicE and their tarsi dilated in 

 the females. Larva furnished with external respiratory organs. 



These insects differ from those of the preceding genera by having 

 the antennae usually considerably longer than the wings and very 

 slender ; the wings are of different shape, being somewhat truncate 

 at the apex, and they are generally destitute of a transverse nerve 

 towards the middle of the costa; the proportions of the joints of the 

 palpi are slightly different; their colours are of sombre hue, the 

 wings not being prettily maculated with yellowish on a brown ground, 

 as in Philopotamus, and the posterior pair have a trifid central 

 nervure. 



Sp. 1. atomaria? Brunnea, infrh ochracea, cano pilosa, alls canescentihus, 

 atdicis ochraceo nigroque maculatis, pedibus flavesceatibus. (Long. corp. 4§ 

 lin.; Exp. Alar. 9—11 lin.) 



Phr. maculata. Donovan, v. xvi. pZ. 548./. 2. — Phi.maculatus. Steph. Cuial. 

 318. No. 3600. — Phi. instabilis. Phil. Mag. (Curtis) v. iv. p. 213. — Hyd. 

 atomaria. Pictet, p. 201. pi. xvii./. 1 ? 



Head and thorax brown, clothed above with greyish hairs, the sides and 

 under surface of the latter ochreous ; abdomen brown above, ochreous 

 beneath and at the apex ; wings pale grey, the anterior with a few more or 

 less indistinct blackish dots and ochreous spots, the former predominating 

 on the costa, and the latter on the inner margin, where are two rather larger 

 brownish blotches, separated by two ochreous ones ; on the hinder margin 

 are also some conspicuous ochreous spots ; legs and antennae pale tawny, 

 the latter annulated with brown ; palpi brown. 



Var. jS. Phi. obliquus. Steph. Catal. 318. No. 3610.— Wings more distinctly 

 spotted, the spots disposed in two somewhat oblique streaks. 



Larva with the head brown, with four azure spots, the three following 

 segments brown, the abdomen greyish-green, its last segment and legs 

 yellowish. 



Found, occasionally, near London, in June and July, but more 

 abundantly in Devonshire and Scotland. 



Sp. 2. tenuicornis. Capite, thorace abdomineque nigricantibus, antennis graci- 

 libits, ochraceis, alls anticis canescentibus, ochraceo nigroque puncfatis, posticis 

 j'usccsccntibus, pedibus ochraceu-j'ulvis, (Long. corp. 4 lin.; Exp. Alar. 10 — 

 11 lin.) 



y2 



