260 



COLEOPTERA 



CHAP. 



Schibdte. Leconte and Horn also adopt this view, except that 

 they treat Throscides as a distinct family. By most authors 

 Eucnemides, Throscides, and Cebrionides are all considered dis- 

 tinct families, but at present it is almost impossible to separate 

 them on satisfactory lines. The following table from Leconte 

 and Horn exhibits the characters of the divisions so far as the 

 imago is concerned : 



Posterior coxae laminate ; trochanters small. 



Labrum concealed ; antennae somewhat distant from the eyes, their 



insertion narrowing the front . . . EUCNEMIDES. 



Labrum visible, free ; antennae arising near the eyes under the frontal 



margin ...... ELATERIDES. 



Labrum transverse, connate with the front. 



Ventral segments six ; claws simple ; tibial spurs well developed. 



CEBRIOXIDES. 

 Ventral segments five ; claws serrate ; tibial spurs moderate. 



PEROTHOPIDES. 



Posterior coxae not laminate ; trochanters of middle and posterior legs vrry 

 long ... ... CEROPHYTIDES. 



Throscides are considered to be distinguished by the 



mesosternum being impressed on each side 

 in front for the accommodation of the 

 posterior face of the front coxae. The 

 genus Throscus has the antennae clavate. 

 The classification of the Elaterides and 

 these forms is a matter of the greatest 

 difficulty, and, if the larvae are also 

 considered, becomes even more complex. 

 Cebrionid larvae are different from 

 those of any of the other divisions, and 

 possess laminate, not calliper-like, "man- 

 dibles. The larvae of Eucnemides (Fig. 

 135) are very little known, but are 

 highly remarkable, inasmuch as it is 

 A iT "er ver y difficult to find any mouth-opening 

 : * .-, in some of them, and they have no legs. 



position of spiracles C TM ,-t T /> 



head more enlarged; D, L lie other dlVlSlOHS possess V61J few Species 



under side of terminal seg- compared with Elaterides. Iii Britain 



ment ; a, aims. , , . . 



we have about sixty species ot Elate- 

 rides, four of Throscides and three of Eucnemides; Cerophytum 

 was probably a native many years ago. Neither Perothopides 



FIG. 135. Larva 

 n. sp. Hawaii, 

 side ; B, under side 



