nils. 



F. II. tiH.wKi.v: I'lis.stillfltic „i //,(■ World. 



79 



The dentition complete in unworn .specimens on liotli mandibles ; 



the mandibles in most species synimetrical ; tiie elvtra often 



hairless except at the shoulders . . . . . . Ophrtjgonitis, p. 86. 



The lowest terminal and anterior lower teeth of the rifrht 



mandible absent, or repre.sented only by very minute 



denticles ; the anterior lower tooth of the left mandible very 



larjje ; the elytra more or less extensively hairy at the sides Acerahis, p. 89. 

 ' The dentition of the left mandible not more reduced than that 



of the right and the ripht outer tubercle at least as large as 



the left ; the mentum without primary scars ; the secondary 



scars very large, more or less completely cutting off the 



median from the lateral pieces, usually more or less linear ; 



the lateral and intermediate areas of the metastcrnum never 



fused 

 Not as above ; the dentition of the right mandilile never more 



reduced than that of the loft 



/The anterior margin of the labnnn with a (frequently indistinct) 



tooth near the middle ; all the elytral grooves deeply 



impressed throughout, at least the lateral ones strongly 



punctured; the pronotal scars hairless; at least one of the 



outer tubercles more or less complex, or truncate with an 



additional tubercle between itself and the anterior angle of 



the same side of the head (Oriental forms) . . . . Pehpides, p. 93. 



The anterior margin of the labrum not toothed ; some at least 



of the elytral grooves feebly impressed and more or less 



obsolete behind, none of them at all strongly punctured ; the 



pronotal scars more or less hairy ; the outer tubercles acute 



or truncate, but never complex or associated with secondary 



tubercles (Celebean forms) . . . . . . Pleslhenus, p. 96. 



The mentum with well developed primary scars ; the lateral 



and intermediate areas of the metasternum distinct . . Mastochilus, p. 97. 



The mentum without definite primary scars ; or, the lateral and 



intermediate areas of the metasternum fused 

 The lateral and intermediate areas of the metasternum fused . . 

 The lateral and intermediate areas of the metasternum not 



fused 

 The dentition of both mandibles complete, normal : mandibles 



more or le.ss symmetrical . . . . Labioiits, p. 103. 



The dentition of both mandibles reduced — especially that of 

 th left one : the anterior lower tooth (when present) widely 

 so]>arated from the middle lower tooth, and ])artially fused 

 with the lowi'st terminal toi tli . . . . . . Protomocailus. p. 107. 



n. 



12. 



' The fusion is less obvious tlmn in the .Amorican forms where it occurs, as the greater pnrt nt least of the posterior 

 intirnirdinte ureas are hairless nnd either smooth or coar.«eIy punctured, while the areas on the ovitcr side ami in front of 

 1lw 111 iir.. v.rv hairy and dni-ilv Imt oimewhat finely puncture<I, 



