•62 AN ACCOUNT OF BRITISH FLIES. 



to the hind border. Halteres dark, with reddish tinge, sometimes 

 slightly yellowish. The base of the femora yellowish beneath, tibiae 

 and tarsi shining white. Abdomen dark reddish-yellow, sometimes 

 almost black. The oviduct is long, having the second and third 

 segments yellowish-white ; no valves. 



The larvae form spongy galls in the stalk and inflorescence of the 

 Barberry (Barbarea vulgaris) during May and June, and, according 

 to Walker, from June to November, in the folded, blister-like galls of 

 Nasturtium sylvestre, also in N palustre and Sisymbriu]ii Sophia. 



The larvae undergo their transformations in the galls, and do not 

 pupate in the ground. 



This species is figured by Winnertz,* and also by Loew in his 

 " Dipterologische Beitriige " (Figs. 8 and 9). 



/ C. Saiicifia, Bouche. 



1 C. Gallarum salicis. 

 Cccidomyia salicis, Schrk. = \ ^ j^^^^^^,.^ ^^^^^ 



\C. Argyrostida, Macq. 



Black ; thorax with two stripes of whitish hairs. This insect is 

 covered by silvery hairs, especially on the legs. In the male the 

 joints of the antennae are 20 to 22 in number ; in the female from 

 22 to 24; half the length of body, longer in the male. The basal 

 joints twice the length of their petioles. Wings pubescent ; trans- 

 verse veinlet at the end of the basal half of the first longitudinal 

 vein. Halteres dark. 



The larvae of this v/illow Cecid form woody galls on the boughs 

 and twigs of Salix aurita, cinerea, caprea, and purpurea. The larvae 

 pupate in the galls— not in the ground, as done by many other 

 Cecids. Mr. Inchbaldt describes the galls as ^' multilocular bosses 

 on the upper twigs of S. cinerea." They appear during June. 



C. acrop/iiia, Wtz. 



Black ; abdomen on ventral surface pink, with flesh-coloured 

 markings on the sutures ; sides of the thorax also pinkish. Antennae, 

 19 to 20 joints; as long as the body in the ^ ; joints and petioles 

 of nearly equal length ; in the ? the antennas are only half the 

 length of the body ; both clothed by whorls of silvery hairs ; wings 

 silvery or whitish in some lights. " Transverse veinlet placed before 

 the middle of the first longitudinal vein ; second longitudinal vein 

 bent forward at its junction with the veinlet ; curved hindward from 

 thence to its tip, joining the costal at some distance from the tip of the 



* " Linnrea Entomologica," 1853 (pi. ii., fig. 4). 

 t Entomologist, 1886, p. 35. 



