Hi INTKODUCTION. 



The corium is mostly bordered by the above-named 

 Hmbus, the absence of which may be used for a generic 

 character, as in Cixms and in Issiis. At the point 

 where the Hmbus ends, the clavns may be taken to 

 begin. The corium has a normal number of five radial 

 veins ; these are set forth by those nervures which 

 proceed directly from the tegulae to the Hmbus, where 

 they end without crossing the marginal nerve. 



Counting from the Hmbus, the elytral cells in series 

 may be thus enumerated : — Apical, sub-apical, dis- 

 coidal, costal, marginal, and basal cells. To these 

 elytral cells, some genera show one or more supple- 

 mental cells. 



The Wings. Unterflligel. 



Venation in these organs is easily traced, except 

 amongst the minute Typhlocybid?e. Occasionally, the 

 texture is in these so delicate and fragile, that some 

 address is requisite to unfold their numerous plications 

 without tearing them and disarranging their order. 



Fieber studied much the venation of the genera he 

 described. He chiefly used the elytra for this purpose, 

 whilst Sahlberg turned his attention more particularly 

 to the wings proper. Of these wings Sahlberg en- 

 graves twenty or more generic examples. 



The wings spring from the metanotum, and, like 

 the elytra, they may be divided into the corium and 

 clavus. The membrane which fills the wing-cells is 

 exceedingly thin, and is often iridescent, whilst the 

 membrane of the elytra is rarely so, but, on the con- 

 trary, often pilose, pitted, or dense. 



Nomenclature of the wing-neuration (or venation 

 of others) will be found in the descriptions of Plates 

 A and B, where also the veining is delineated. 



In further explanation of Plate A, fig. 12, the letters 

 have the following references : — i and /'. Open cells of 

 the clavus. r. Anal wing-cell. o. Sutural wing-cell. 

 s, ty u. Subapical wing-cells. 



