372 COLEOPTERA OF NORTH AMERICA. 



work in order that the North America fauna may be completed, 

 as no colleetious from this island have reached the authors of 

 the Biologia Centrali-Americana; two species are known. 



Sub-Family III.— TENEBRIONIN^. 



In this sub-family the posterior margin of the third and fourth 

 ventral segments is coriaceous; the middle coxffi are usually pro- 

 vided with a distinct trochantin, and their cavities extend out- 

 wards to reach the epimera; sometimes (Ulomini) the trochantin 

 i.s absent, but in these cases it appears rather to be united with 

 the mesosternum, than to be absolutely wanting,, as in the first 

 sub-family; the middle coxae are in no case so closely embraced 

 by the sterna as in the TeutyriidiE. The body is more frequently 

 winged than apterous, and, consequently, the metasternum is 

 more frequently long than short ; the mentuni is small, or, at 

 most, moderate in size, and does not conceal either ligula or 

 maxillae; the gular peduncle is always distinct. The anterior 

 eoxai are sometimes oval or subtransverse, a character not seen 

 in the other two sub-families; equally peculiar to this sub-family 

 is the short, coriaceous clypeus seen between the front and labruni 

 in certain tribes. It is here too that the first instances occur of 

 genera with entire mandibles. The tarsi are ])ubescent beneath, 

 sometimes silky, very rarely spinous or setose. 



A large number of the species are found under bark; the first 

 four tribes are, however, found on the ground 

 Our tribes may be separated as follows : — 



Front entirely corneous. ^• 



Front with a coriaceous margin or a coriaceous band between it and the 



labrum. 11- 



2. First joint of tarsi moderate or ebmgate, never very short, tarsi not 



compressed ; gena? not snlcate. ^• 



First joint of tarsi short, tarsi compressed; gen;e snlcate. 



XII. BOLETOPUAGINI. 



3. Eyes h'ss promineiit than the sidi-- of frrnt, more or less transverse, 



always eniarginate in front. '^• 



Eyes more prominent than the sides of front, usually rounded, feebly 



or not emarginate. XI. Diaperini. 



4. Anterior tibise alone or none dilated. ;>■ 

 Tibia; all more or less dilated, fossorial. X. TRAcnYSCELiM. 



