212 COLEOPTERA OF NORTH AMERICA. 



Palpi with the last joint elongate, securiform ; metathoracic episterna 



wide in front, strongly triangular. 2. 



Palpi with the last joint oval pointed ; metathoracic episterna narrow ; 



claws simple. 3. 



2. Claws appejidiculate ; mandibles toothed. Trypherus. 

 Claws simple. Lobetus. 



3. Mandibles toothed, head wide, nari'owed behind. Malthinus. 

 Mandibles simple, head not narrowed behind. Malthodes. 



Fam. XLV.— malachiidae. 



Mentum small, quadrate, corneous; ligula prominent; 

 palpi 3-jointecl. 



Maxillae exposed at the base, with two unarmed lobes ; 

 palpi moderately long, 4-jointed. 



Antennae inserted upon the front at the sides, generally 

 before the eyes; usually serrate, and 11-jointed. 



Head exserted, prolonged into a short broad beak; eyes 

 rounded (emarginate in some foreign genera); mandibles 

 small; labrum distinct; epistoma separated from the front 

 by a transverse suture, and frequently, in whole or in part,, 

 membranous. 



Prothorax not foliaceous at the sides; prosternum short, 

 not extending between the coxae; coxal cavities large, trans- 

 verse, open behind. 



Mesosternum short, oblique, flat, side pieces attaining the 

 coxcc. 



Metasternum short, side pieces usually wide, epimera 

 scarcely visible. 



Elytra sometimes entire, sometimes abbreviated. 



Abdomen with six free ventral segments; the sixth indis- 

 tinct in some genera of the second tribe. 



Anterior coxae large, conical, contiguous, with distinct 

 trochantin ; middle coxae contiguous, conical, prominent; 

 posterior coxae transverse, conical, and prominent inter- 

 nally; not covered by the thighs. 



Legs moderately long, slender; tibiae with indistinct ter- 

 minal spurs; tarsi 5-jointed (the anterior ones in the males 

 of certain foreign genera, 4-jointed), filiform ; the fourth joint 

 entire (except in a few foreign genera); claws usually each 

 with a large inferior membranous appendage. 



This family was first established by Erichson, under the name 

 Melyridaj, and though considered by I.aeordaire as only a per- 



