140 MYCETOPHILID.E. 



The larvae caused much damage in the gardens by devouring 

 lily bulbs and other plants of a like nature. The following notes 

 have been compiled by Mr. C. Paiva, of that Institution, who 

 observed the trans formations : 



" During February 1910, I placed a number of males and some 

 egg-laden females in a tube with a piece of a rotten lily-bulb, with 

 the object of getting them to breed. All the flies died in the 

 course of a couple of days. I could not tind any eggs, but I kept 

 the bulb damp and on about the 4th March I noticed a number 

 of small thread-like worms, quite transparent, with black heads, 

 moving about quite actively in the soft and moistest parts of the 

 bulb. These gradually grew larger and I preserved some in spirit. 

 On March 14th, at 10 A.M. I found the tube with a number of 

 flies similar to those which I had placed in the tube in February 

 for the purpose of breeding. They were very active and ran 

 about on the sides of the tube. At first I thought they were trying 

 to escape, but I watched them more closely and found that the 

 males were running after the females. No difference in the size 

 of the abdomen of the male and that of the female could be noticed 

 when the flies were first observed, but as the day advanced the 

 abdomen of the females gradually enlarged. 



The most striking feature in the life of these little flies, seems 

 to me to be mode of copulation. The act is effected by the male 

 running blindly, as it were, until he approaches a female. He 

 gets on her back and after effecting the connection, in a few 

 seconds, gets off and being still attached to the female, struggles 

 to release himself. N"o sooner has one male left a female than 

 another male comes running along and attaches himself to the 

 same female. In this manner I have observed several males to 

 have connection with the same female. I have also noticed two 

 males attempting to copulate with one female at the same time."* 



100. Sciara impostor, sp. nov. 



c?. This species has a remarkably close resemblance to S.flavi- 

 collis, although on account of the 1st longitudinal vein ending 

 short of the fork of the 4th, it technically tails into the second 

 section of the genus. The distance between the tip of the 1st 

 longitudinal and the fork is, however, so small that the distinction 

 may easily be overlooked, owing to the close resemblance between 

 the two species in other respects. 



The chief difference is that in S. flavicollis, the whole thorax, 

 except the margin, is uniformly shining black, whereas in the 

 present species the black colour is distinctly dull, and is composed 

 of three contiguous, very broad, black stripes, occupying nearly 

 all the dorsum. Moreover the central stripe is (in two out of the 

 three specimens) dark bi'own at its anterior end, which, attaining 



* Mr. Dale says that he has seen in Euglancl two males of a Sciara actually 

 in cop. at the same time with a single female. 



