204 INSECTA. 



of its four anterior feet, which are free, and furnished with thick 

 fringes of hairs. The nymphs of the large species leave the water 

 altogetlier, and climb on various bodies, where their final change is 

 effected. The small ones simply rise to the surface, where they are 

 transformed to winged Insects, in the manner of the Culices and va- 

 rious Tipulariee ; their exuvium serves them for a boat. 



In some the inferior wings are evidently wider than the others, and 

 plaited. 



Sericostoma, La 



Where, in one of the sexes, the maxillary palpi are in the form of 

 valvulge, covering the mouth in the manner of a rounded snout, and 

 triarticulated ; under them is a thick and cotton-like down. Those of 

 the other sex are are filiform, and consist of five joints *. 



Phryganea proper. 



Where the mouth is similar in both sexes, and the maxillary palpi 

 are shorter than the head and thorax, and but scarcely pilose. 



P. grandis ; Roes. ; Insect., II, Ins. Aq. cl, 2, xvii. The largest 

 species in France ; antennae as long as the body ; superior wings 

 greyish-brown, with cinereous spots, a longitudinal black stripe, 

 and two or three white dots at their extremity. 



The tube of its larva is invested with little pieces of bark, or 

 ligneous matter arranged horizontally. 



P. striata, L. ; Geoff., Insect., II, xiii, 5. About an inch long; 

 fulvous ; eyes black ; nervures somewhat darker than the rest of 

 the wing. 



P. rhomhica; Roes., Insect., II, Ins. Aq., cl, 2, xvi. Length 

 seven lines, and of a brown yellow ; a large, white rhomboidal, 

 and lateral spot on the superior wings. 



The tube of its larva is covered with little stones and frag- 

 ments of shells f . 

 Certain species, such as the filosa, quadrifasciata, longicornis, 

 hirta, nigra, have excessively long antennae, and maxillary palpi also 

 extremely long and densely pilose. They form the subgenus 



Mystacida, Lat. 



In the others the four wings are narrow, lanceolate, almost equal, 

 and without plicae. To this division belongs the 



Hydroptila, Dalm., 



Where the antennze are short, almost granose, and of equal tliick- 

 ness :}:. 



Another subgenus — Psychomyia — might be formed of Phryganese 

 with similar wings, but in which the antennse are long and setaceous, 



* A genus established on a species from the environs of Aix, sent to me by M. 

 Boyer de Fons-Colombe, and which has been also brought from the Levant by M. 

 de Labillardi^re. 



t For the other species, see Fabricius, De Geer, and Rcesel. 



X Anal. Entom., p. 26. 



