148 COLEOPTERA OF NORTH AMERICA. 



Saprinus, Plegaderus, Teretrius, and Acritus occur on both 

 sides of the continent; Abraeus is represented by one species in 

 California : the other genera have thus far been found only in 

 the Atlantic region. 



Fam. XXX— nitidulidae. 



Mentum transverse, subquaclrate, composed of two pieces 

 closelj united together, frequentlj^ rounded, sometimes sin- 

 uate or emarginate in front. 



Maxillas usually exposed, rarely covered at the base; 

 usually with only one lobe, the outer lobe being wanting; 

 but in the first tribe the outer lobe is distinct. 



Antennas inserted under the margin of the front, 1 1-jointed 

 (the eleventh indistinct in Rhizophagus), terminated by a 

 round or oval club, composed of three, rarely of two joints. 



Prothorax sometimes closely applied to the elytra, some- 

 times passing over their base; prosternum frequently pro- 

 duced behind, side pieces not distinct; coxal cavities open 

 or closed. 



Mesosternum separating the middle cox^e, side pieces with 

 the epimera large, extending to the coxte. 



Metasternum short, side pieces narrow, epimera not visi- 

 ble. 



Elytra sometimes truncate, sometimes entire. 



Abdomen with five free ventral segments, the first a little 

 longer, widely produced between the posterior coxte. 



Anterior coxse transverse, separated, not prominent; the 

 middle and posterior transverse, flat, distant, the latter 'ex- 

 tending almost to the margin of the body. 



Legs short, somewhat stout, retractile, or subretractile; 

 tarsi short, dilated (except in some genera of the third tribe), 

 hairy beneath, usually djointed, with the fourth joint very 

 small ; the posterior tarsi of the males of Rhizophagus 4- 

 jointed, in Cybocephalus all the tarsi 4:-jointed, and in Smi- 



crips 3-jointed. 



The species of this family live on decomposing substances. 



Antennfe 11-joiiited, terminated by a 3-jointed club; tarsi isomerous, 

 similar in the two sexes. 

 Tarsi 5-jointed. 



Labrnm free, more or less visible. 



Maxilhe with two lobes; antenna; feebly capitate. Bkachypterij.i. 



