1904.] 



105 



coating lying flat, and tliat. Uie nuislirootns expand and ihr poat. itself thickens (by 

 absorption of air ?) after it is laid. 



This idea is supported by some of Iho niushrounis having a form not of a mush- 

 room, but of a chantarcllc, /. e., wineglass-shaped, as though they had not fully 

 expanded (3). 



This coating reminds one very much of the snowy portions on the eggs of 

 Microptertfx. In Micropteri/x these are much more delicate, and destroyed by a 

 touch. One may suppose both to have the same purpose, which is jjrobably to 

 prevent the egg actually touching a too wet surface. 



The larva is about 12 mm. long, long and slender (OU mm. thick), spindle- 

 shaped, i.e., thickest at the middle, but thinning to either extremity in a long curved 

 sweeping outline continuous from end to end. It varies a good deal in length during 

 its movements. The head is a well marked separate structure, with well developed 

 mouth parts, and whilst under examination it keeps spinning silk by a slapping 

 motion of the head against the surface under the thoracic segments. 



The twelfth segment is small, the 13th much smaller, whilst the 11th is a mere 

 small appendix, yet has a small conical addition beyond it (or part of it) ; this 

 extremity seems usable as a pseudopod. There are no hairs, feet or other appendages 

 and movement seems to be of a vermiform character, the under surface is pale 

 and apparently adapted to glide over the prepared silken way. The dorsum is dark 

 in a pattern varying somevv'hat from segment to segment. The recurved and 3i*d 

 abdominal segments have indications of subsegmentation into two equal portions, 

 and this is very marked in 5tli, 6th and 7th, which are longer than the others. 



Some of the dark dorsal chitinous patches seem to be rather stiff and solid, but 

 the paler portions of skin are quite flexible, but not collapsible. 



Pupa of Mycetophilid fly, February 22ncl, 1904. lu a cocoou 

 consisting of a very spider-like silk tissue, three quarter inch long and 

 half inch broad. The cocoon is smooth inside, i. e., the pupa is in a 

 cavity and not hung amongst threads. There is no cremaster. 



The pupa (5, 6) is about 4"3 mm. long and 1"2 mm. wide. Form 

 somewhat cylindrical, abruptly truncate in front, tapering behind, more 

 dorsally than ventrally for the last 1'5 mm. Seen dorsally the meso- 

 thorax is large, 1 mm. in length, front 

 angles rounded, and spiracular points 

 just showing beyond. The metathorax 

 is narrow, then follow the abdominal 

 segments, of which the first six are of 

 about equal diameter, the Gth narrowing 

 as a beginning of the rounding of the 

 posterior extremity. The first abdominal 

 segment has no spiracle, i. e., it is be- 

 neath the wing ; the next six (2-7) have 

 spiracles elevated on slender cones ; a 



