102 THE ORDER OF COLEOPTERA. 



Tlie Ptini proper subsist ui)ou substances in a state of incipient decay, 

 and are often found in cellars and out-buildings. The Anohii are usually 

 found in wood more or less decayed; but the Bostriehi bore into solid 

 wood, and are often seriously injurious, more especially to forest trees. 

 Indeed, the last mentioned insects bear so striking a resemblance, both 

 in their short cylindrical forms and their eminently wood-boring habits, 

 to the short-horned wood-borers fScolytidwJ, in the tetramerous section, 

 that one feels strongly tempted to place them in the latter tribe; but in 

 the details of their organization they are more closely allied to the more 

 highly organized Ptinidai, especially in the more fully developed anten- 

 nal club, labrum, and maxillary palpi. The larvse also have six feet, 

 whilst those of the Scolytid?e are footless. 



The following are the principal genera: 



A. Antennai flliform, sometimes branched. Tibial spurs very small or wanting ; tarsi distinctly 

 5-joiuted. 

 B. Head and thorax much narrower than the elytra ; antennae filiform and simple and inserted upon 



the front, and about as long as the body Ptinus, 8 sp. 



BB. Form cylindrical or sub-globular. Antenna) usually either branched or with the three last 

 joints longer than the others, and inserted before the eyes. 



C. AntenniB simple, but with the three terminal Joints elongated Axoisir.M, 22. 



C C. Antenna' branched iii the male, serrate in the female Ptilinus, 3. 



A A. Antennip terminating in three larger and somewhat serrate .joints ; tibial, spurs distinct j tarsi 

 apparently 4-jointed. Thorax asperous. Elytra often truncated and toothed behind : 



BOSTKICHUS, 19. 



The Ptinus fur^ Linn., is three-twentieths of an inch long, light brown, 

 with two whitish bands across the elytra, interrupted in the middle. The 

 thorax is uneven, having a tubercle on each side and two on the back. 

 This insect feeds upon almost all kinds of dried animal matter, and is 

 often very iujurious in museums of natural history. It was originally a 

 native of Europe, but has become disseminated over the civilized world. 

 We have a very similar species in this country, the humcralis, of Say, 

 which is regarded by some as only a variety of the European species. 

 We have also another common species, often found in company with the 

 others, in cellars and out-buildings. This is the Ptinus hrumieus, and is 

 distinguished at once from the others by being wholly of a light-brown 

 color, and destitute of the bands on the elytra. 



Our most common species of Auobium is the A. tenuestriatum, Say, 

 scarcely three-twentieths of an inch in length, of a uniform, cinnamon- 

 brown color, with a microscopically fine silken pubescence, and the 

 elytra with fine impressed lines or striiTe. This species is also ii^jurious 

 to cabinets and herbaria. It may often be caught upon the wing in or 

 about our houses. 



The genus Bostrichus contains a number of small species, which, in 

 their larva state, are genuine wood-borers, and some of which are se- 

 riously injurious both to fruit and forest trees. The B. hicaudatus, a 



