HORX-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 

 flimily of Urocerid.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 antennas 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 qnite CAdindrical ; 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 belly, which is furrowed to receive it. The 

 borer usually extends some distance beyond the end of the 

 body, and C(insists of five pieces. The two outermost are 

 grooved within, and, when shut, form a hollow tulje 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 strong and elastic as wire, have several small teeth 

 along the lower side towards the end. These needles, 

 ajid the back in Avliich 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, wdierein they drop their eggs. Their 

 young ai'e 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 



