596 
THE STUDY OF INSECTS. 
the pygidium of both sexes is undivided, and may be cov* 
ered or uncovered by the wing-covers, but is not surrounded 
at the edge by them, as in the Scolytidae; the tibiae are not 
serrate; the antennae are elbowed ; and the labrum is want¬ 
ing. The larvae of the larger species bore in the stems of 
plants, while those of the smaller species infest grains and 
seeds. 
Among the more common members of this family are 
several species of the genus Sphenophonis (Sphe-noph'o-rus); 
one of these is represented by Figure 727. These are 
of medium or rather large size, and are often marked 
in a very characteristic manner by longitudinal, 
elevated bands of darker color. 
One of the most important members of the family, 
Fig. 7 2 7 . { r om an economic standpoint, is the Rice-weevil, Ca - 
la?idra oryzce (Ca-lan'dra o-ry'za^). This is a small snout- 
beetle, measuring only one fifth inch in length. It is usually 
black, but sometimes it is of pale-chestnut color, or some 
shade between the two. It is exceedingly abundant, espe¬ 
cially in the Southern States, where it does great injury to 
stored grain of all kinds. 
Family ScolytiDjE (Sco-lyt'i-dae). 
The Engraver-beetles . 
If the bark be pulled from dead branches or trunks 
of trees, the inner layer and the sap-wood will be found 
to be ornamented in many cases with burrows of more or 
less regular form. These smoothly cut figures are the 
mines of the engraver-beetles. Many kinds of these engrav¬ 
ings can be found, each characteristic of a particular kind of 
engraver-beetle. A common pattern is shown in Figure 728. 
The beetles that do this work are mostly of cylindrical 
form and of small size ; many species are almost microscopic, 
and the larger ones rarely exceed a quarter of an inch in 
length. They are usually brown, sometimes black; and 
