BRITISH FLIES 31 



Numerous valuable notes and descriptions of larvte have been given in 

 Part I. of a most excellent work, Dipteea Danica, published by Lundbeck 

 in 1907 — Stratiomyidce to Cyrtidm of this present volume — but unfortun- 

 ately it is now too late for me to make many quotations, or to refer the 

 following paper back to Dr Sharp. 



On the Metamorphoses of the Diptera Brachycera 



INCLUDED IN THIS VOLUME 

 AND OF THE 



Platypezidw, Fiptinciilidcv, and Syrphidce 

 by D. Sharp, M.A. 



Figures 54, 59, 60, 61, 65, 66, and 69 are copied from original 

 drawings made by Miss M. A. Sharp. 



Larvae. 



I. — Introdltctory. 



In the volume of this series — (British Flies, vol. viii., 1901)— 

 previously published, the author summarised on pp. 1-6 the Yiews of 

 Brauer as to the classification of Diptera. 



Brauer's system was believed by himself to be a natural — if not a 

 completely final one; and notwithstanding the just criticisms to which 

 it has been subjected it still holds the field. Its chief fault is the division 

 of the great orders into two — and only two — primary divisions.* This 

 fault was in part probably due to Brauer's method of working by means 

 of dichotomic tables. In the summary given (as mentioned above) by 

 Mr Verrall, he alluded on p. 3 to the difficulties of comprehending 

 Brauer's tabular work ; and I fully agree with what is there said. 



Brauer's system is largely leased on the early stages. And he has 

 published tables of these, which he considered to be a complementary 

 part of his system. In the summary given by Mr Verrall these tables of 

 metamorphosis were not included. He now thinks it desirable they should 

 be given, at any rate in part. 



We have therefore prepared a translation of those portions that 

 relate to the groups dealt with in this volume, and to the Syrphidtv, 

 Flatypezida', and Pipunndida\ the families monographed by Mr Verrall 

 in vol. viii. 



The knowledge of Dipterous metamorphosis is still very incomplete, 

 but it has made some progress since the publication, in 1883, of Ih-auer's 

 tables. We have therefore added some explanatory and supplementary 

 notes relating to the families it is now our object to elucidate. 



The larvte of Diptera are in every case destitute of jointed legs. They usually 

 have the head of peculiar shape, small, or even to all appearance quite absent. The 

 larvte that most resemble them are the maggot-like larva? of C'urcu/ionnke. The 

 larv£e of Curcidimiidce have little or no power of locomotion, whereas Dipterous 



* Since this was written Professor Miall's criticism of Brauer's two divisions has appeared in Tr. Ent. Soc, 

 Loudon, 1907, p. 273. I quite agree with this distinguished savant in considering the two divisions, Orthor- 

 rhaplia and Cyclorrhapha, at present incomprehensible. 



