12 OUR HOUSEHOLD INSECTS 



of very similar appearance to Anobium, sometimes does 

 considerable damage to woodwork. It is especially partial 

 to willow-wood, in which it 

 makes neat cylindrical burrows. 

 It is called Ptilinus pectinicornis, 

 and the specific name refers to a 

 remarkable peculiarity in the 

 antennae of the male, the sex 

 which, for a reason that will 

 appear presently, is most com- 

 monly seen. It may be recog- 

 nised by its extremely cylindrical 

 FIG. 4 .-Ptiiirms pectinicornis reddish-brown body and rather 



(male). * 



swollen black thorax (Fig. 4). 



The antennas are marvellously beautiful. Instead of 

 being composed of a mere string of simple joints, such 

 as constitute those of the allied species, and, in fact, 

 of beetles in general, they appear, when fully spread 

 out, like two pieces of deep fringe. This results from 

 each joint, except the two at the base and the one 

 at the apex, carrying a lateral appendage generally 

 far longer than itself. The apical joint is itself of the 

 same form as these appendages, so that altogether there 

 are nine of them ; but the one nearest the base is much 

 shorter than the rest, and seems little more than like a 

 stout tooth ; while the last seven, which are of nearly 

 equal length, are several times as long as the joints 

 to which they belong. Antennae of a similar character 

 occur in a few other British beetles, though in none is 

 the peculiarity so greatly exaggerated as in the present 

 species. 



It is not easy to conjecture the raison d'etre of this 

 remarkable feature, for there seems to be little in the 

 habits of the insect to account for its differing from its 



