FT eR Bg ee ee a ee ey eee eee 
THE MYCETOPHILIDE. 99 
swollen part—the rectum. 1 failed to find any traces of MJa/phigtan 
tubules in Mycetophila. 
The Mervous System is composed of nine ganglia. Dufour says 
they are distributed as follows: one in head, two in thorax, and six 
in abdomen. In the mycetid I examined this was certainly not the 
case. There are certainly “wo cerebral ganglia, two thoracic, and 
only five in the abdomen. This is the normal number for the /ingi- 
cole, Whether Cerof/atus is abnormal in having ten, or whether 
Dufour miscalculated the cerebral ganglia I have not been able to 
make out, as I have not had any live Cerof/ati to examine. 
The Respiratory System.—There are eight pairs of stigmata, two 
thoracic and six abdominal, from which proceed delicate trachee. 
I have been unable to make out their distribution. The 9? sexual 
organs are composed of two long and rugose glandular ovaries, 
opening into a long neck and passing into an oviduct, which can be 
extended by the 9°. 
Internal Anatomy of Larve. 
The mouth parts of the larva consist of the following parts: A 
fleshy labrum in a horny frame; a pair of horny, serrated mandibles ; 
a pair of maxillz and an upper lip (Fig. 14). Dufour, in his descrip- 
tion of Cerop/atus, figures two large eyes in the larva. ‘These are 
wrongly described, they only being the bases of the antennz. Into 
the mouth open /wo salivary glands ; these are long, tubular struc- 
tures, often as long as the body; but in one species I examined 
(Sciophila ?) they were not so long. The walls of the glands seem 
to be simple. No doubt these have some function in the web- 
spinning of the larve, and possibly manufacture the fluid that forms 
the thread for the web as well as a fluid for digestive purposes. I 
failed, however, to find any difference in the structure of the cells 
that would justify this conclusion. The esophagus is narrow, but 
soon passes into a large crop with corrugated walls, somewhat in- 
flated. The crop is preceded by a small, almost globular tract, 
which I take to be the proventriculus. Into the base of this open 
four czeca, which are evidently the same as the proventricular ceca of 
the tipulid larva, Dufour in his Cerof/atus larva only figures two of 
these long ceca. The stomach is large, and its walls are much 
folded. Into its base, or distal extremity, open the efatic ceca. I 
was unable to make much of these in the J/ycetophila larve I 
examined. There are certainly four ceca, but whether they united 
into a single pair before entering the stomach, as shown in the figure 
of Ceroplatus, or entered as four separate tubes, as is usually the 
7—2 
