A 
od 
of the first and second portions a large series of long stout hairs arises which 
I have termed the dasa/l tuft. At the junction of the second and _ third 
portions there are generally two large and very stout hairs or spines. I have, for 
descriptive purposes, termed these the medzan spines. From the end of the 
third portion, one or more spines project. I have called these ¢erxminal spznes. 
There is also, at the extreme end of the antenna, a papilla, which may be 
large and conspicuous, possibly a sense organ. I have named it the termznal 
papilla (Pl. II, fig. 16). 
The antenne are often very small and poorly developed. In the case of 
some species (Stegomyza) this appears due to retrograde changes, since most 
of the above-mentioned structures are represented only by small hairs or spines. 
The Thorax.—The thorax is more or less globular in shape, and greater in 
diameter than the abdominal segments. The exact size and shape depend upon 
the genus concerned. On each side, arising from papilla, are three main series 
of large, stout hairs. The papilla, from which these arise, may or may not 
carry a stout spine resembling a thorn, The hairs are of various lengths in 
different species and may be simple, .branched, or feathered. On the whole 
they do not appear to be very important from the point of view of ascertaining 
the affinities of different genera. - In addition to the above there are usually a 
few small hairs which arise immediately behind the head and overhang the 
occiput. In certain species (open water species, e.g., Melanoconton Tenzor- 
-hynchus) these are large and may form very prominent objects in the living larvz, 
projecting to a great distance and appearing to act as tactile organs. 
The Abdomen.—The first seven abdominal segments do not appear to be of 
sufficient importance to be described in detail in the present connection, In 
the Anophelzna oar-like feathered hairs arise from the first three segments. 
This sub-family also differs from all other Czlzczdae in having palmate hairs 
on some or all of the segments. The eighth and ninth segments require 
separate mention. 
The eighth abdominal segment.—This segment is profoundly modified by 
the presence of the respiratory openings and their armature. In all genera but 
the Anophelzna a tube carries the spiracles to a distance from the segment. 
This tube has usually been called the respiratory szphon or sephon tube. 
The siphon tube consists of an unbroken tubular piece of chitin of varied 
shape and size in different species. It usually carries a few smali branched 
hairs, and on the posterior aspect, on each side of the median line, there are 
two rows of conspicuous spines, the number of which is of specific importance. 
Each of these spines, is a compound one consisting of three or more long tooth- 
like processes. Their actual shape seems to be much the same, even in widely 
different genera, but their appearance varies considerably with the different points 
B 2 
