NOTIPHILINA. 131 



' Second joint of the antennae unguiculated at the end, or at least, the 



upper side of the intermediate tibiae beset with a few strong bris- 



1 . ties. I. NOTIPHILINA. 



Second joint of the antennae not unguiculated, the intermediate tibiae 



never have long bristles on the upper side. 2 



f Eyes hairy, oral cavity never of considerable size, anterior femora never 



2 1 incrassated. II. HYDRELLINA. 



( Eyes naked, oral cavity generally very large. III. EPHYDRINA. 



The second joint of the antennae is called unguiculated (unguicu- 

 latum) if it bears on its end a bristle directed forward, whether it 

 be thickened and long, or thin and short. In the latter case it is 

 often difficult to perceive, particularly in the genera Paralimna 

 and Corythophora, which in the whole structure of their heads 

 approach very much some genera of Ephydrina; yet the presence 

 of several long bristles on the upper side of the intermediate tibiae 

 and the color and markings of their abdomens point out too 

 evidently their relation to the species of the widely spread genus 

 Notipkila, to be overlooked. The hairy eyes will be sufficient 

 in general to enable us to recognize the Hydrellina ; in those 

 genera, the species of which have densely pilose eyes, the hairs 

 are often exceedingly short; but their presence even then is easily 

 known by the whitish reflection shown by the outline of the eyes. 

 In the genera with scattered hairs on the eyes there are some spe- 

 cies in which it is very difficult to perceive the single small hairs; 

 in order to distinguish them with certainty from the Ephydrina, it 

 is to be borne in mind that in the latter the eyes are much more 

 rounded, that their faces are narrowest just where the antenna3 

 are inserted, and considerably increase in breadth immediately 

 below, whereas the Hydrellina have always more oblong eyes, and 

 their faces have -their least breadth beneath the antennas; the oral 

 cavity also is never so strikingly wide as in most genera of Ephy- 

 drina; moreover the clypeus in those species of Hydrellina which, 

 on account of the indistinctness of the pubescence of the eyes, 

 might be taken for Ephydrina, is very little developed. 



I. NOTIPHILINA. 



The second joint of the antennas distinctly unguiculated, or the 

 presence of some long bristles on the upper side of the interme- 

 diate tibiae will refer any species to the present section, the genera 



