152 COLEOPTERA OF NORTH AMERICA. 



Tribe VII.— SMICRIPIIVI. 



Labrum moderately prominent. Maxillic one-lobed. Mentuni 

 transverse coueealing the niaxillas. AntennsB eleven-jointed with 

 a three-jointed club. Tarsi three-jointed. Anterior coxal caTi- 

 ties open behind. 



An aberrant tribe liaving a tendency tow^ards Monotomida?. 

 But one species, Smicrijjs palmicola Lee. is found in Florida on 

 Chamaerops palmetto, and was previously described by Eeitter, 

 Berlin' Ent. Zeitschr. IS'IG, 301, as Tisiphone hyiMcoproides 

 from Cuba, but the generic name is preoccupied. 



Tribe VIII.— RHBZOPIIAGI^I. 



Labrum visible at the tip of the epistoma but connate with it. 

 Mandibles simple at tip. Maxillae with two lobes, the outer 

 slender not capitate. Antennae ten-jointed, club of two joints, 

 the tenth partly inclosed ; antennal grooves short, convergent. 

 Prostenium not prolonged at tip. Anterior coxal cavities closed 

 behind. Mesosternum horizontal. Intercoxal process triangular, 

 acute. Abdomen with the first and fifth segments long, the inter- 

 mediate three short, equal. Elytra truncate, pygidium exposed. 

 Tarsi feebly dilated, heteromerous in the males, pentanierous in 

 the females. Claws simple. 



The males in addition to the tarsal character have an additional 

 segment and the head usually larger. 



One genus, Rhizophagus, constitutes the tribe, and is repre- 

 sented on both sides of the continent; the species live under 

 bark. This tribe is related to Ti'ogositidte, but the 1st tarsal 

 joint is not shorter than the second. 



Fam. XXXL— trogositidae. 



Mentum transverse, subquadrate; ligula small, corneous. 



Maxilla with two lobes, the inner one sometimes very 

 small; palpi short, 4-jointed. 



Eyes usually reniform (divided in some foreign genera). 



Antennas inserted under the frontal margin, 11-jointed, 

 rarely 10-jointed (in some foreign genera); the last three 

 joints widened, forming a loose club, of varied form. 



Prothorax not passing over the base of the elytra; side 

 pieces not distinct; coxal cavities closed in the first and 

 third sub-families, usually open behind in the second; pro- 

 sternum separating the coxae. 



