70 AN ACCOUNT OF BRITISH FLIES. 



C.pteridis, Mull.= C.filicina, Kief. 



Imago unknown. Miiller describes the larvae as reddish in colour, 



living in the " rolled " and " laid down " leaflets of the fronds (ot 



Pteris). One larva in each leaflet. The leaf-rolls are at first green, 



then they become cigar-shaped and reddish, and as soon as the 



larvse pass to the earth they become black. Perris* describes the 



habits as follows : " Au mois de juin, en observant avec soin les 



feuilles de la grande fougere, Pteris aqtdlina, on remarque ^a et la 



des folioles roulees en dessous d'un peut cote, la partie roulee etanl 



ordinairement brunatre, ce qui la rend plus apparente. Si on la 



deroule avec precaution on met a decouvert une larve Cecidomyie 



d'un blanc rose." 



/C. querais, Lw. 



1 C. rodoris, Hardy. 

 C. pustulariss Bremi = - „ ^ . -r, u 



^ ' C. reapenciis, Isach. 



\C. hiflexa, Rudow. 



Imago unknown according to Bergenstamm. Hardy gives an 

 account of this in the " Scottish Gardener," iii., 1854, which I have 

 been unable to obtain. The larvae are said to live chiefly in the 

 leaves of the oak ; the lobes of the leaf being folded and laid down 

 on the under side, forming a hollow for two or three larvae. The 

 folds are paler than the leaf. The larvae pupate in the earth. 



C. thalidri, Traill. 

 As far as I can make out this only appears to have been mentioned 

 by Low.t Bergenstamm says, " Imago unbekannt." The larvEe 

 live in the deformed fruit of Tlialid) ujn. 



C. mice, Schrk. = i ^- ^^^>'^^^<^^'"' \ Macq. 

 ( C. excavans J 



The imago likewise unknown. Concerning the larvae Walker 

 says : " In June the galls]: of C. tilice are not uncommon on the 

 young shoots growing from the stumps of lime-trees by the banks of 

 the Wye, near Chepstow. They are round or oblong, green on one 

 side, bright red on the other. Some of them contain more than 

 twenty separate cells, each inhabited by one larva. The latter is 

 about one line of length, of a bright yellow colour, and has the 

 faculty of leaping, like the larva of Piophila. It is full grown in the 

 tliird week in June." 



Bergenstamm says : " Die Larven leben gesellig in dem nach oben 

 eingerollten Blattrande von Tilia enropcza." 



* Tr. Ent. Soc. Fr., 1870, p. 180. f D. B. iv., 1850, p. 30. 



X Ins. Brit. Diptera, iii., p. 130. Bremi in his monograph figures the galls of 

 C' tiliacea on the leaf of T. Etiropcea in several stages. 



