﻿Summary. 



The Elaterid larvæ are recognized: ^) by the form of 

 their mouth-parts, especially maxillæ and labium, ^) by having 

 bifore spiracles *), and ^) by the shape of 9**^ abdominal 

 segment. 



2 types of Elaterid larvæ occur: a biconvex one, rather 

 broad in proportion to the length, and a cylindrical roundish 

 one. — The biconvex form ist the most original, having 

 both epipleurum and hypopleurum well divided, as well 

 mutually as from tergum and sternum. Sternum in the 

 most original of these larvæ (i. e. Agrypnini, in all cha- 

 racters a well limited group) is divided in 4 sclerits, con- 

 verging backwards, but in the others it forms a single 

 sclerit. In all biconvex forms there is a large soft connec- 

 ting membrane between the sclerits, these larvæ therefore in 

 a distended state show large white or pale parts of the body. 

 In the cylindrical larvæ the sclerits have coalesced so that 

 each segment only has 1 dorsal semicircular hoop composed 

 of tergum and epipleurum, between which often a fine 

 sutural furrow can be seen, and 1 ventral hoop composed of 

 the coalesced hypopleural and sternal sclerits. As the con- 

 necting membrane between these 2 hoops is very small and 

 as the hoops are very strongly, brownish or yellowish chiti- 



*) Spiracles of the bifore type have at first been described by 

 Schiedte (see f. i. Naturhist. Tidsskrift III R. 3. B. p. 152 and 

 passim) and the description later on essential points supple- 

 mented by Beving (Natural History of the larvae of Donaciinae. 

 Intern. Revue ges. Hydrobiol. u. Hydrogr. 1910 p. 63). 



