1 70 AN A ceo UNT OF BRITISH FLIES. 



entomologists, both in its pre-larval life as well as during its trans- 

 formations, and we shall consider this subject more fully when dealing 

 with their larval life. 



The characters of the family are briefly as follows : Head small and 

 often retracted under the thorax, which is without any transverse 

 suture. Ocelli absent or rudimentary. Wings long, narrow, costal 

 vein ending near the tip of the wing, no veins along posterior margin. 

 Antennas with from six to fifteen joints, which are densely pectinated 

 in the males, but often simple in the females and smaller. Legs long 

 and slender, tibiae and tarsi nearly cylindrical. 



The following are the synonymous names of the family : 



Chironomidce. 



TtpularicB culicifortnes, Mg., Macq. 

 Ctilicites, Newman. 

 Tipulidce, Leach. 

 Chironomii, Zett. 

 ChiroJW?nince, Roud. 



The geological distribution is, strange to say, wide, we naturally 

 should not expect to find any traces of such delicate insects as the 

 "midges" we are considering in the rocks of any remote period, 

 such, however, is not the case, for even in Mesozoic rocks we find 

 representatives of these delicate flies. The Lias of Dobbertin fur- 

 nishes us with a species referred to the genus Macropeza, and another 

 species of the same genus has been figured by Brodie from the 

 English Purbecks. The latter author also figures from the same 

 horizon two possible Chiro7ioini. There are also two other species 

 possibly belonging to this family, namely, Cecidoniium grandceviuji, 

 Westwood, and Corethrium pertifiax, Westwood, from beds of 

 Purbeckian age. But as in many other fossil insects, of which we 

 have only fragmentary remains, there is some doubt as to their true 

 relationship, they might possibly be intermediate types between the 

 Chironomidce and Culicidce. The species figured by Brodie under 

 the name of Rhyphus prisctis is most probably a member of this 

 family and not of the family to which Brodie referred it. 



When we reach the Tertiary beds we find a very difierent aspect ; 

 as we should expect, the amber, which is such a wonderful preserver 

 of insect life, contains many of these delicate flies, some in a beautiful 

 state of preservation. Loew has described several species of Tanypus 

 and many of Chironomus and Ceratopogon. Burmeister and Giebel 

 also record the presence of the two latter genera in amber. Not only 

 do we find the perfect insects but also the pupae in a state of perfect 

 preservation, and occasionally a maggot has been found. Besides 



