PTINIDAE. 201 



Head retractile, frequently protected by the prothorax ; 

 oral organs usually small ; epistoma sometimes distinct ; 

 labrum distinct in all of our genera. 



Prothorax with the side pieces not separate; lateral margin 

 none in the first tribe, distinct in the second; coxal cavities 

 rounded, open behind. 



Mesosternum small, oblique; side pieces not attaining the 

 coxae. 



Metasternum moderate or long, side pieces narrow. 



Elytra entire; epipleurae distinct, sometimes very broad. 



Abdomen with five ventral segments, the first not elon- 

 gated. 



Anterior and middle coxae cylindrical, or subglobose, 

 moderately or but slightly prominent, without trochantins; 

 posterior coxae transverse, not prominent or dilated inter- 

 nally in the first; sulcate behind for the reception of the 

 thighs in the second ; slightly prominent internally in the 

 third and fourth sub-families. 



Legs contractile in the second sub-family, frequently long; 

 trochanters in the axis of the thighs ; tibiae slender, with the 

 terminal spurs sometimes small, sometimes large; tarsi 5- 

 jointed, but with the first joint small in the third and fourth 

 sub-families. 



A family containing species, mostly of small size which live on 

 vegetable matters in an incipient stage of decay ; many are there- 

 fore found about houses, and have been transported by commerce 

 over the whole globe. The form varies greatly according to the 

 sub-family. 



Four sub-families are indicated as follows : — 



Antennae inserted upon the front. Ptinidae. . 

 Antennas inserted before the eyes ; 



Tibiae without spurs. Anobiidae. 

 Tibiae with distinct spurs ; 



First ventral segment scarcely longer. Bostrichidae. 



First ventral segment elongated. Lyctidae. 



Sub-Family I.— PTINIDAE. 



These insects are of small size, with the head and thorax com- 

 paratively small. The antennae are inserted upon the front, long, 

 not serrate, and rather stout. The legs are long, not contractile, 

 with the trochanters large ; the tibiae have the spurs obsolete ; in 



