i IK. I 4ITB0 STATES. 1(17 



or sculpture If, consequently, any doubl still remains in the determination of the 



it results from the inherent difficulty of the subject, which would not be removed b\ a 



iter amount of detail. 



Proceeding now to the principles employed in the classification of the Bpecies, we must 

 first inquire into the natural limits of the group. 



The family of Elateridae has always been considered as closely allied to the Buprestidae, 

 in which also the presternum is prolonged posteriorly and received into the excavated me- 

 ternum; neverthel ss, on comparison, great differences are found: in the Buprestidae 

 although the anterior coxae are small and globular, the acetabula in which they are re- 

 ceived are composed partly of the epimera ot" the mesothorax, while in Elateridae the 

 tabula, although open posteriorly, are confined to the prosternum; the prothorax thus ac- 

 quires a greater degree of mobility than is seen in the Buprestidse: tbe same Btructun 

 : in the Throscites that ha^ been just noticed in the Buprestida?. Other different 

 are seen in the structure of the abdomen : the suture between the firsl and second ses- 

 ments is more or less obliterated in Buprestidse, while in all Elateridse it is as distinct as 

 the other sutun 



From the other groups of serricorn pentamerous Coleoptera, the Elateridse are distin- 

 guished by the small globular anterior coxa' and the | I pro rnum. The combi- 

 nation then of the four following characters will define the family, as understood by me: 



Coxce antic;v parvse rotundatse, nin contigurc in prosterno sil ibulia pi stico hientibaa : | 



ternum pone coxaa productum, praecipue mucronatum, in mesostcrno exi 

 suturis ventralibaa omnibus dietinctis; tarsi 5-articnlati. 



This definition includes the so-called families of Eucnemides and Cebrionides, which 

 differ by unimportant characters, from the genuine Elaterides. The vali f then' cha- 

 racters will be presently dis npanying the four essential characters ab 

 given, there are others ofgn tancy, such as: 



The antenna' are serrate, flabellate, or p ctinate, rarely subfiliform, never clavate, or 

 capitulate; in the males only of certain Eucnemides are the terminal joints enlargt d, bul 

 they a I way- preserve thi ir serricorn t\ pe. The eyes are round, (in Pcrotbops alone are they 

 fitly oval.) and never emarginate; the antenna' are inserted in fovea', the upper mar- 

 gins of which are more or less defmed, usually undi ide of the front, immediate!) in 

 front of the eyes; in Eucnemides the fovea becomi ius, which contract- the front at 

 the middle, and the antenna' approach each other, thus becoming farther removed from 

 tbeeyes. The mandibles are usually small and retracted; in Cebrionides they are loi 

 and prominent ; the labrum is distincl in the true I '.ht. rides, indistinct in the other groups; 

 the prosternum is lobed in nearly all of the true Elaterides; not lobed in Campylus, < I 

 tod< s, Eucnemides, and Cebrionides; the head is d< flexed, and the month entin I) cov< r< d 

 in the Eucnemides (except Melasia and Tharops;) it is applied against tbe lobe of tbe 

 prosternum, and consequently moderately deflexed in most Elaterides; not deflexed, but 

 free in Campylus, ad in tin' Cebrionides; the posterior thighs ai tile 

 under the dilated p 1 pt in Cerophytum, where th 



: the plate is slightly emarginate, and usually toothed at the interna! ihu« 



vol.. x. — G 



