154 COLEOPTERA OF NORTH AMERICA. 



Alindria is represented in the Atlantic region only, the other 

 genera occur on both sides of the continent. 



Tribe II.— PELTIIVI. 



Oval, flattened, or rounded convex insects, having always a 

 flattened margin; the front is truncate; the last three joints of 

 the antenna} form a loose perfoliate club. The anterior coxal 

 cavities are open behind, except in Calitys. 



Mentuni transverse, emarginatc ; anteniial grooves feeble ; 



Front tibise w^itli terniinal hook. Peltis. 



Front tibiae without terminal hook ; 



Front coxal cavities closed. Calitys. 



Front coxal cavities open behind. Grynocharis. 



Mentum minute, oval ; antennal grooves deep ; 



Front coxal cavities open behind; front tibise without hook. 



Thymalus. 



The species of the genera, except Thymalus, are flattened; the 

 elytra are striate, with square punctures in the first; tuberculate 

 in the second, with the sides of the body serrate; the last genus 

 is convex, with the elytra irregularly punctured. 



Fam. XXXII.— monotomidae. 



Mentum moderate, subquadrate, rounded or subangulated 

 iu front; ligula partly corneous, prominent; labial palpi 

 short, 3-jointed, first joint very small. 



Maxilloe exposed at tlie base, with two lobes, the outer 

 one long, slender, scarcely ciliate at tip, the inner one larger, 

 ciliate internally and at the tip; maxillary palpi 4-jointed, 

 the first joint very short. 



Eyes strongly granulated, rounded. 



Antennse inserted under the sides of the front, behind the 

 mandibles, 10-jointed, the last one or two joints forming a 

 club. 



Head tolerably large, flat, suddenly but slightly constricted 

 behind; front broadly lobed between the mandibles, which 

 are short, acute, and fringed with membrane internally; 

 labrum very short, not distinct ; mandibles short, robust, 

 acute at tip, with a small subapical tooth ; internal margin 

 fringed with hair. 



Prothorax with the side pieces not separate, prosternum 

 entire, coxal cavities small, broadly closed beliind. 



