202 



COLEOPTERA OF NORTH AMERICA. 



the first tribe the first joint of the tarsi is not shorter than the 

 second. The hind coxas are transverse, and are covered by the 

 thighs, in repose. The flanks are continuous with the pronotum. 

 Two tribes may be separated thus : — 



Antennas very approximate. 

 Antennae distant. 



Ptinini. 



EuCKADINI. 



Tribe I.— PTUVINI. 



The antennae are very approximate at base, long and filiform ; 

 the elytra when glabrous are very much inflated, and embrace the 

 sides of the trunk very widely, leaving the ventral segments very 

 small and narrow. 



Our genera are : — 



Antennas approximated, filiform ; head tuberculate ; 

 Elytra inflated, smooth, shining, glabrous ; 



Thorax smooth, glabrous. Gibbipm. 



Thorax tuberculate, pubescent. Mezium. 



Elytra punctured, pubescent ; 



Teeth of the mentum rounded, labrum emarginate. Niptus. 



Teeth of the mentum acute ; labrum rounded. Ptinus. 



The first joint of the tarsi is long in Ptinus, but only equal to 

 the second in the other genera. 



Gibbium scotias is imported from Europe, as are some of the 

 species of Ptinus, which genus is however generally diffused. 

 Niptus is represented by one New Mexican species. 



Tribe II.— EUCRADINI. 



Eucrada humeralis Lee. (Hedobia humeralis Mels.), while 

 evidently related to the preceding tribe, differs by having the 

 antennae widely separated at the base, serrate in the female, but 

 with the tip of the 3 — 10 joints prolonged in the male, so that 

 the organs become pectinate ; the thorax is tuberculate, the elytra 

 are cylindrical, and do not embrace the flanks. The trochanters 

 are moderate, the tibiae are terminated by a single large spur ; 

 the first joint of the tarsi is long. 



Sub-Family II.— ANOBILDAE. 



The insects of this sub-family are generally of a cylindrical 

 form, though some of the species of Dorcatoma, and especially 



