CECIDOMYIA. 73 



beautifully iridescent ; veins in their last subdivisions not more than six ; 

 costal vein extending nearly to the tip of the wing, or to the hind border ; 

 subapical vein almost always obsolete. 



These flies are the most elegant and delicate little creatures in 

 the whole of the Diptera. The species are exceedingly numerous, 

 and generally of very minute size. Descriptions of the characters 

 and habits of all the British species would alone fill this volume, 

 but only a few of these have as yet been observed, and it is diffi- 

 cult to identify them with most of the published descriptions, and 

 I am not able to refer to collections for specimens of them. The 

 larvae are generally fleshy, oval grubs, rather attenuated in. front, 

 and without any exserted appendages ; those of many species feed 

 on various parts of living plants, and are thus more or less in- 

 jurious to vegetation ; some of them form galls, others feed on 

 decayed wood. The pupa resembles the imago, but its form is 

 much more contracted, with the wings and legs very short, and 

 resting upon the breast, in distinct cases. Winnertz has published 

 the most complete treatise on this family, and has reviewed the 

 works of nearly all the previous authors thereon. 



The genera may be grouped thus : 



("Distinct 1. CECIDOMYIA. 



Cubital vein j 



(.Obsolete 2. LASIOPTEEA. 



The only recorded genera in addition to these are Spaniocera 

 and Heteropeza of Winnertz, and Brachineum and Ozirhynchus of 

 Eondani, which have not been discovered in Britain. 



Genus I. CECIDOMYIA. 



CECIDOMYIA, Latr. Gen. Cr. iv. 253 (1803); Meig. ; Mcq. ; Loew ; 

 Winn.;Zett. Tipulay., L. ; F.(Sp. I. et E. S.); Gmel.; D. G. ; Sckr. 

 Chironomus p., F. (S. A.). Macrocera p., Meig. Kl. Cecidomyia et 

 Lasioptera p., F. (S. A.) Cecidomyza, Zett. Oliyoirophus, Latr. 



Caput parvum. Oculi lunati, apud verticem contigui. Ocelli nulli. 

 Proboscis brevis, crassa. Palpi 4-articulati ; articulus primus brevis ; 

 secundus et tertius plerumque sequales ; quartus ssepissime longior. 

 Antennae longse, 13-36-articulatee, moniliformes aut filiformes, ple- 

 rumque verticillato-pilosse. Thorax rotundatus, normunquam gib- 

 bosus aut antice productus. Ala; ampla3, saapissime ciliatre ; vena 

 costalis ake apicem plerumque attiugens ; subcostalis apud costye 

 dimidimn tenninata ; cubitalis costali ad apicem connexa ; subapicalis 

 saepissime nulla ; subanalis simplex, nonnunquam obsoleta ; analis 

 furcata, raro apicem versus obsoleta. Halteres magni. Abdomen 

 segmentis 8, plerumque lineare. Pedes sa?pissime longi, graciles ; tibia? 

 non spinosa? nee calcaratee ; metatarsus brevissimus. Mas. Antenna) 



VOL. IV. L 



