of the British Hydromyzidae. 



219 



cated by the satiny lustre of the minute scales which clothe 

 the face and sides. I consider as the type of the group the 

 Ephydra riparia, the feet of which are formed peculiarly for 

 resting on the surface of pools. The larvae of most Ephydrce 

 live among the semi-fluid green matter, which mantles on the 

 surface of stagnant waters, or in the mud at the bottom. 

 Desvoidy assumes, that the other genera of the family in their 

 larva state are nourished by the living tissue of phanerogamous 

 plants; but this view rests on conjecture and a solitary fact 

 observed regarding a species of Notiphila. The firm and ho- 

 mogeneous texture of the face indicates but little sensibility to 

 smells, from which we may probably conclude that the larvae 

 are not eminently saprophagous. 



' Fam. MUSCID.E. 



Areolets or Cells. 



«, humeral. 



b, subcostal. 



c, mediastinal or ulnar. 



d, radial. 

 f, cubital. 

 y, radical. 



e, praebrachial. 

 i, pobrachial. 

 o, anal. 



u, discoidal. 

 g, k, Ic, external. 

 I, m, axillary. 

 n, axillary lobe. 



Nerves, 



1° Excurrent or Main Nerves. 



1, costal. 



2, subcostal. 



3, mediastinal. 



4, radial. 



5, cubital. 



7, praebrachial. 



10, pobrachial. 



12, anal. 



13, axillary. 



2° Recurrent or Cross Nerves. 



14, humeral. 



6, praebrachial. 



8, pobrachial. 



9, discoidal. 



11, subanal. 



Tribe HydromyzidyE, Fall, 

 Calyptra auricula interiore quasi nulla *. Nervus media- 

 stinus cum subcostali connatus, alee i longitudinem vioc per- 



tingens. 



* A little more apparent in Ochthera. 



R 2 



