596 



COLEOPTERA OF NORTH AMERICA. 



following groups may be established, in all of which the antenna; 

 are 1 1-jointed : — 



Front coxal cavities witli an outer fissure. 2. 



Front coxal cavities without fissure, trocliantin not visible. 5. 



2. Front coxse separated by prosternum. 3. 

 Front coxse contiguous. . 4. 



3. Third antennal joint longer than 4th. Penthes. 

 Third antennal joint equal to 4th. SYNCHEOi^i. 



4. Frontal suture distinct ; trochantin visible. Melandky^e. 

 Frontal suture and trochantin not visible. Serkopalpi. 



5. Front coxse contiguous. Diec.e.i:. 

 Front coxae separated by prosternum. Orchesi^. 



Group I.— Penthes. 



We have placed as a separate group the genus Pentlie, repre- 

 sented by two velvety black, flattened, oval species, found under 

 bark in the Atlantic States; the more common one, P. obliqnata, 

 is readily known by the scutellum covered with orange-colored 

 hair. 



These insects resemble in appearance gigantic Mycetophagi, 

 and have been classed by previous authors among the Tenebri- 

 onidse; the anterior coxal cavities are widely open behind. 



The antenuce are not thickened externally; the 3d joint is as 

 long as the 4th and 5th together; the 7-10 are rounded, the 11th 

 is a little longer, and is pale at the tip; in the male the joints 

 4-7 are compressed and broader than the others; the maxillary 

 palpi are moderate in length, and but slightly dilated-; the ante- 

 rior coxiE are oval and separated by the prosternum ; the middle 

 coxse are equally distant, and the hind coxas are less distant; the 

 tarsi are filiform, the penultimate joint not being lobed ; the 

 claws are simple; the tibial spurs are short. 



Group II. — Synchroae. 



This group contains but a single species, Synchroa punctata 

 Newman {Melmidrya umbriva Mels ), from the Atlantic States. 

 The form is elongate, like an Elateride of the genus Melanotus, 

 coarsely punctured and pubescent; the head is prominent and 

 horizontal; the maxillary palpi are moderate in length, and but 

 slightly dilated; the antennae are long, slender, and feebly serrate, 

 and the third joint is not longer than the fourth; the anterior 

 coxse are oval and separated by the prosternum, which is also 



