664 DIPTERA OF AUSTRALIA, 



and fungi. West wood (Mod. Class. Ins. II.) says that he has 

 observed the "transformations of several species of Molohrus, 

 Latr. (Sciara, Meig.), the larvse and pupae of which are found 

 under the bark of felled trees, or at the root of decayed veget- 

 ables." Olivier (Prem, Mdm. sur quelques Ins. qui attaquent les 

 Cereales, 1813) bred three species of Sciara from wheat. 

 Macquart (Hist. Nat. des Insectes Dipt. I.) says that the larvse 

 of Sciara develop in the earth ; this is confirmed by Schiner (In 

 Beitr. Mon. der Sciarinen von Joh. Winnertz), when he declares 

 that the garden soil is seldom free from them. To undergo their 

 metamorphosis into the pupa state sbme of the larvae construct a 

 cocoon, but others do not ; of four species meutiont d by Bouche 

 only one makes a cocoon. Dufour (Ann. des Sc. Nat. 2nd Ser. 

 t. 12, 1839), in a paper on the metamorphoses of Diptera, describes 

 the stages of S. iiiyeruia, the larva of which constructs a cocoon. 

 According to Ferris, S. convergens envelopes itself in a whitish, 

 pellucid cocoon, which it makes in the detritus. The cocoon is 

 not formed of filaments, but of a mucous substance wliich the 

 larvge secrete, after the manner of those of Sciopliila. 



II. Pupa. 



The pupa is naked, oblong, and exhibits a general appearance of 

 the different parts of the imago, — the eyes, antennae, rudimentary 

 wings and the feet being plainly distinguishable. The pupa is at 

 first yellowish-white, amber-yellow, orange or pale reiidish ; after- 

 wards the above-mentioned organs become brown. Two more or 

 less distinct horns appear near the base of the iantennjie in most 

 pup*. Surface of the abdomen minutely .shagreened, witli micro- 

 scopic asperities, the last segment bifid. Stigmata generally 

 indistinct. The thorax splits for the whole of its length en the 

 emergence of the imago. The pupse have a close I'esemblance to 

 those of the Cecidomyidse. 



III. Habits and habitats oj the jierject insects. 



The perfect insects are obtainable in Australia all the year round, 

 but the greatest number of species and individuals have been 

 obtained in the neighbourhood of Sydney during the spring of the 



