60 FAMILIES OF PETALOCERA WHICH LIVE 



Capitulo triphyllo, ovato, transverso, lamellarum 

 disco utrinque sapius convexo. 



Labrum coriaceum, exsertum, s&pius hirsutum. 



M andibulse cornea, crasscz, valida, intus arcuata, inter- 

 dum dentatcc, apice acutissimo. 



Maxillae laciniis duabus, interna cornea unidentata vel 

 dentibus instructa, interdum unco corneo valido 

 processus hujus loco ; lacinia externa vel membra- 

 nacea et vix fimbriata, vel cornea et ciliis spinuli- 

 formibus aut dentibus corneis armata. 



Palpi maxillares maxillis longiores. 



Palpi labiales articulo ultimo ovato, plerumque crassi- 

 ore. 



Mentum irregular e. 



Caput subquadratum, Clypeo brevi, antice convexo. Cor- 

 pus ovatum, plerumque valde gibbum, subtus pla- 

 num ; Coleoptra maxima, gibboso-convexa, forni- 

 cata, ad latera undique deflexa, ano ipso obvoluto. 

 Thorax transversus ; Scutello distincto. Pedes 

 forma variantes ; tibiis anticis s&pe dentibus haud 

 munitis. 



Observations, 



The Trogida, though by no means a family having such 

 strong general characters impressed on it as either of those 

 we have hitherto considered, may nevertheless be distin- 

 guished from them all with considerable facility. Their 

 antennae in the first place have the lamella of their clava 

 convex on both sides ; so that the three joints of which this 

 is composed are always very distinct; whereas in the Geo- 

 trupida the first and second joints of the clava are ope or 



