202 THE CANADIAN ENTOMOLOGIST. 
large and bears two very large and prominent compound eyes. These 
eyes, which consist of many thousand facettes each, are so large that they 
meet on the upper surface of the head. This great power of vision is 
still increased by three simple eyes, or ocelli, situate on the upper surface 
of the head. From the front part of the head project two short, tapering 
antennae. The mouth occupies the front under surface of the head, and is a 
most formidable structure. The upper lip is broad, and conceals very 
powerful tcothed organs, called mandibles; other organs of the mouth are 
also armed with strong teeth which enable the creature to satisfy its carniv- 
orous desires. The most remarkable portion of the mouth, however, is 
the lower lip, a large, flat, lobed organ, closing the mouth from the under 
side, and which may be projected forward to a comparatively great 
distance when attacking other insects. 
The thorax, or middle portion of the body, is three or four times as 
long as the head, and very much greater in diameter. It resembles the 
head in colour, being a medium chocolate shade, and is sparsely clothed 
with very short hairs of the same hue. 
The abdomen, or posterior part of Z. #rimaculata tapers very gradually 
to the end, and is much smaller in diameter than the thorax, but more 
than twice its length. The colour is slightly paler, and is relieved by a 
line of pale yellowish blotches along each side, which gradually become 
smaller in size toward the end of the body. The upper surface is arched, 
while the under is flattened. . 
The legs are six in number, and are attached three to each side of the 
lower surface of the thorax. 
The wings, which are four in number, are attached two to each side of 
the upper surface of the thorax, and are about one and a quarter inches 
long, and three eighths to nearly half an inch in breadth; the front ones 
being slightly the narrowest. The substance of the wings is a very deli- 
cate net-work covered by a thin transparent membrane having a shining 
surface. From the place of attachment of each wing there proceeds a 
narrow elongated patch of a deep brown colour, while from about the 
middle of the wings there is a large irregular patch of the same colour, 
which extends completely across. The structure of the wings combines 
great strength with lightness, thereby enabling the insect to fly with very 
great rapidity. Their shining surface, transparency, and brilliant colouring 
in this and other members of the same order, combine to give them a 
