38 CALIFORNIA ACADEMY OF SCIENCES. 



captii)le of being flexed or straigliteueil at pleasure, and, in 

 contradistinction to the former, such an antenna might be 

 called ^Icxlhlij (jvitlculate. 



IJasal jiiiiit (if the anteuu;i3 greatly elongated, sub ('(jual in length to the next 

 three or four together; anteunaa strongly and anteriorly geuienlate. 



Neck broad Hespeiobium. 



Neck narrow Ababactus. 



Basal joint of the autennie not greatly elongati-d; antenuai posteriorly and 

 more or less strongly geniculate. 

 First four joints of the posterior tarsi sub-eijual, first not longer than tho 

 second. 

 Neck rather broad. 



Prothorax sub-quadrate or slightly elongate; labruiu bilobcd 



Lathrobium. 



Prothorax narrowed from ajjex to base; labriim truncate, not dent- 

 iculate, having along the lower edge of its anterior margin four 

 widelj'-spaced, very short, broadly rouiuled callosities, and, m the 



middle a very small, rounded emarginaticni TrachYSectUS. 



Neck very slender. 

 Prothm'ax gradually narrowed anteriorly; labruui quadrideutate. 



Scopseus. 



Hind tarsi with the first four joints decreasing more or less gradually in 

 length. 

 Prothorax narrowed in front. 



Labrum quadrideutate Echiaster. 



Labrum bidentate Stilicus. 



Prothorax sub-quadrate, anterior and pt)sterior angles more or less nar- 

 rowly rounded. 

 Labrum having four ratlu'r large sul)-e(pial tectli; elytra much longer 

 than the pronotum. 

 First jiiiut of the posterior tarsi very slightly longer than the second. 



Or US. 



First joint of the posterior tarsi sul)-equal in length to th(> next two 



tog. ther Caloderma. 



Labium with two ])airs of miu ;te approximate teeth; elytra no longer 



than the pronotum OligOpterUS. 



Ijiibrum liidiMitate; elytra variable ill b'Dglh Lithochai'is. 



Labruui unideiitate; elytra longer tliau tiie pronotum. Metaxvodonta. 

 Labrum rounded; acutely emar^inate at lip; elytra as long as the 



pronotum • DaCllOChiluS. 



Labrum entiie; elytra shoiter than the pronotum.. . LiparOCephaluS. 



