Platychirus. 193 



corr. Bltt. 1834, 10) but I have not seen this paper. Malm mentions 

 (Ent. Tidskr. I, 1880, 70) that he has bred F. scambus from a larva, 

 fomid on excrements from a patient immediately after the stool, but 

 this niay be quite accidentally. Zetterstedt mentions (Dipt. Scand. II, 

 748) that he has bred P. dypeatus from a pupa sitting on the leaf of 

 a grass. I have myseif bred P. alhimanus from a pupa found among 

 old leaves in a garden on '^^/4, the imago came first in May; Mr, Sehlick 

 has bred the same from flood refuse, the imagines came in May; 

 further I have bred dypeatus from a larva found in flood refuse, 

 chiefly of reeds, in a fen on ^^'s, it pupated in the room on ^U and 

 the imago came on ^^U\ other larvæ of this species and M«>«a.r^ma^ws 

 were taken in the same v^ay on "^U on a common near the shore, 

 and on ^"^/4 in a fen, the imagines came in the first half of May; Mr. 

 Kryger has bred dypeatus from larvæ in flood refuse, taken on ^/2, 

 they pupated on ^^U and the imagines came on ^°/4; Mr. Sehlick bred 

 the same species from larvæ in flood refuse in fens, the imagines 

 developing in April and May, and he has bred immarginatus and 

 fulviventris likewise from larvæ in flood refuse in fens, the imagines 

 of the former came in April and May, of the latter in May; finally 

 Mr. Kryger has bred peltatus from a pupa found on the ground in a 

 wood on ^/:5, it developed on ^'^/s, and Mr. Schick has bred the same 

 species from larvæ in flood refuse, the imagines developing in April 

 and May. — The larva (of dypeatus) is of a length of about 10 mm 

 or more; it is somewhat flat below, more arched above, attenuated 

 towards the head and less towards the end ; it is transversely cor- 

 rugated and the dermis is finely chagreened; above and on the sides 

 there are some small and short spines, placed w^ith regular intervals 

 on some of the corrugations in transverse rows; as far as I have 

 been able to see these small spines are placed in the foUowing way: 

 on two of the first segments (the meso- and metathoracal) is on each 

 a transverse row of six spines on one corrugation and some at the 

 sides; on the following segment, the first abdominal, is likewise a 

 transverse rov^ of six spines on one corrugation; but on the next six 

 segments the arrangement is such that the two middle spines are 

 placed on one corrugation, the two on each side more backwards, on 

 the next corrugation; each of these seven abdominal segments has 

 three spines at each side, two anterior, one beliind the other, the 

 foremost quite small, and one posterior higher upwards; each of 

 these segments seems to have four raised corrugations divided by 

 furrows, and the spines are placed on the two middle corrugations. 

 Below there are about seven slight transverse swellings more or less 

 divided in the middle and armed with some very small spines. There 



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