416 
the study of insects . 
being left to poison the atmosphere, is transformed into 
myriads of living beings, whose swift flight and delicate 
forms lend life and beauty to the landscape. 
SYNOPSIS OF THE DIPTERA. 
The Straight-Seamed Flies.—F lies in which the pupa escapes 
from the larval skin through a T-shaped opening, which is 
formed by a lengthwise split on the 
back near the head end and a crosswise 
split at the front end of this (Fig. 484), 
F,G - 4 8 4. or r arely through a crosswise split be¬ 
tween the seventh and eighth abdominal segments, adults without 
a frontal lunule.* Suborder Orthorrhapha (Or-thor'rha-pha). 
The Long-horned Orthorrhapha or Nematocera (Nem-a-toc'e-ra). 
Flies with four- or five-jointed pendulous palpi and with many- 
jointed antennae, which are usually long. The segments of the 
antennae, except the basal two, are similar in form, and are more 
than six in number; they are often fringed with hairs or 
bristles.f 
* The frontal lunule is a small crescent-shaped piece immediately above 
the antennae, which is characteristic of the second suborder, the Cyclor- 
rhapha. In most of the members of this suborder there 
is a suture separating the lunule from that part of the head 
above it, the frontal suture; and frequently this suture 
extends down on each side to near the mouth (Fig. 485). 
But as the suture is wanting in several families of the 
Cyclorrhapha, it is often difficult to determine whether 
the lunule is present or not. The following statement 
will enable the student to recognize nearly all of the 
. . , - . . Fig. 485. — Head 
members of the first suborder. showing frontal 
The suborder Orthorrhapha includes :— suture 
All flies in which the antenna are more than three-jointed, not counting 
a bristle or style borne by the third segment. 
All flics with three-jointed antenna in which vein III is four-branched. 
Such of the flies in which vein VII a appears like a cross-vein, or curves 
back towards the base of the wing, as lack the suture above the antenna. 
This section includes only a few Empidida and the families Dolichopodida and 
Lonchopterida. Nearly all of the flies in which vein VII 2 is of the form 
described here possess the suture above the antenna, and hence belong to 
the Cyclorrhapha. 
f The two types of antenna characteristic of the Nematocera and 
Brachycera respectively are: connected by intermediate forms. These 
