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 Fig - 6 7»- 
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, Amphicenis bicandattis 
(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 serricorne (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 CUPESIDiE (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 LvMEXYLID/E (Lym-ex-yl'i-dae) is also a very 
small family. It is represented in this country by only 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. 
