THE MYCETOPHILID.E. 99 



swollen part — the rectum. I failed to find any traces of Malp/iigian 

 tub ides in Mycetophilcc. 



The Nervous 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 two cerebral ganglia, two thoracic, and 

 only five in the abdomen. This is the normal number for the Finigi- 

 eoLc. Whether Ceroplafus 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 Ceroplati to examine. 



The Respiratory System. — There are eight pairs of stigmata, two 

 thoracic and six abdominal, from which proceed delicate tracheae. 

 I have been unable to make out their distribution. The ? 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 ? . 



Internal Anatomy of Larvw. 



The mouth parts of the larva consist of the following parts : A 

 deshy labrum in a horny frame ; a pair of horny, serrated mandibles ; 

 a pair of maxillae 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 antennae. Into 

 the mouth open tivo 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 larvae, 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 a-sophagus 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 proventriciilus. Into the base of this open 

 four cieca, which are evidently the same as the proventricular caeca of 

 the tipulid larva. Dufour in his Ceroplatiis larva only figures two of 

 these long cajca. The stomach is large, and its walls are much 

 folded. Into its base, or distal extremity, open the hepatic cieca. I 

 was unable to make much of these in the Mycetophila larvae I 

 examined. There are certainly four caeca, 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 



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