COLEOPTERA. 553 



The family Ptinid^e (Ptin'i-dae) or the Death-watch 

 Family is composed of small insects, which rarely 

 exceed a quarter of an inch in length, and very many 

 of them are not half that length. They are usually 

 of a cinnamon-brown color, but not always so. The 

 most distinctive structural feature is the position of FlG - 6 7 i - 

 the trochanters, which are situated between the femora and 

 coxae, instead of at one side of the base of the femur in each 

 case. These insects usually live upon dead vegetable matter, 

 and frequently upon that which has begun to decay ; but some 

 bore into solid wood, and others attack living plants. One 

 of the latter is the Apple-twig Borer, Amphicerus bicaudatus 

 (Am-phic'e-rus bi-cau-da'tus), which often injuriously affects 

 the twigs of apple-trees ; the adult beetle is about three 

 tenths of an inch long, and the male has two thorn-like pro- 

 jections from the ends of the wing-covers. The Cigarette 

 Beetle, Lasioderma serricome (Las-i-o-der'ma ser-ri-cor'ne) is 

 a serious pest in tobacco manufactories, infesting the dried 

 tobacco-leaves and the manufactured products. Sitodrepa 

 panicea (Si-tod're-pa pa-nic'e-a) is a cosmopolitan species, 

 which feeds on many kinds of dead organic matter, both 

 animal and vegetable. It sometimes assumes the role of a 

 bookworm. We have bred it in large numbers from the 

 cover of a very old book, a copy of Dante's Divine Comedy 

 printed in 1536. It seems that old books are much more 

 subject to the attacks of bookworms than others. 



The family CUPESID^E (Cu-pes'i-dae) includes only four 

 American species. These are found under the bark of de- 

 caying trees, and sometimes in houses. The body is covered 

 with small scales; other characteristics are given in the table 

 of families. 



The family Lymexylid^e (Lym-ex-yri-dae) is also a very 

 small family. It is represented in this country by onty three 

 species. Its chief interest lies in the fact that it includes 

 the Ship-timber beetle, Lymexylon navale (Ly-mex'y-lon na- 

 va'le) of Europe. 



