HORN-TAILS. 533 
form and in habits, is very striking and remarkable. Hence 
the saw-flies plainly show the relation existing between the 
orders Lepidoptera and Hymenoptera, and serve closely to 
connect them together. 
The next piercing insects to be described belong to the 
family of Uiiocerid.e, or horn-tails, so called because they 
have a horny point at the end of the body. The Ger- 
mans call them wood-wasps. Their antennae are slender, 
and thread-like, or tapering. They have a large head, 
convex before, and flat behind where it joins the thorax. 
Their wings are long, narrow, and strong, and overlap on 
the top of the back, when closed. The body is very long, 
and nearly or quite cylindrical ; the thorax and the after 
part of the body are of equal thickness, and are closely 
joined together. The horn, at the end, is short, and coni- 
cal or triangular, in the males ; longer, and sometimes 
spear-pointed, in the females. Moreover, the latter are 
provided with a long, cylindrical borer, hinged to the mid- 
dle of the bally, which is furrowed to receive it. The 
borer usually extends some distance beyond the end of the 
body, and consists of five pieces. The two outermost are 
grooved within, and, when shut, form a hollow tube or 
scabbard to the others, one of which represents the two 
backs of the saws of the saw-flies, joined together, and 
encloses two needles for boring holes. The part serving 
for a back to these needles is notched on each side, and 
the needles themselves, which are as fine as a hair, and 
as stron <>• and elastic as wire, have several small teeth 
alone- the lower side towards the end. These needles, 
and the back in which they play, are so connected as to 
appear to be only a single spear-pointed awl. With this 
complicated and powerful tool the females bore holes into 
the trunks of trees, wherein they drop their eggs. Their 
young are cylindrical and fleshy grubs, of a whitish color, 
with a small, rounded, horny head, and a pointed and 
horny tail. They have six very small legs under the fore 
