GENUS ETJUKA. 209 



apex, readily enable it to be distinguished from the 

 Alpine species. ~FromN. crassispina it may be known 

 by the white mouth, longer tarsi and spurs (which are 

 almost straight), longer antennae, and by the stigma 

 not being unicolorous. 



Mr. J. B. Bridgman bred this species from oval 

 green galls found on sallows at Brundall. He sent me 

 a few galls which he thinks are those of the above 

 species, but I have not managed to rear the flies. 

 They do not differ to any appreciable extent from 

 those of N. gallicola, on Salix caprea. 



Genus EUUKA. 



Euura, Newman, Ent. Mag., iv, 259 (Jan., 1837). 

 Cryptocampus, Htg., Blattw., 221. 

 Nematus, pt. Thoms., Hym. Sc., i, 165. 



AntennaB 9-jointed. Wings with one radial and three cubital cellules ; 

 the first of the latter small, the second long and receiving both recur- 

 rent nervures ; lanceolate cellule petiolate ; hind wings with two median 

 cellules. Cerci generally longish. 



Except in having the second cubital cellule very 

 long, this genus does not differ in any tangible point 

 from Nematus. The species have generally the stigma 

 white at the base, and the cerci longish. They are 

 gall makers, forming the galls in the leaf-stalks, in the 

 twigs, or in the leaf-buds. Fourteen European species 

 have been described, and others are also known from 

 North America, and one from Mexico. They are 

 difficult to discriminate, and a revision of the European 

 species is needed. 



Synopsis of Species. 



1 (4) Edge of pronotum white. 



2 (3) Cerci longish, more than four times longer than broad, pro- 



jecting beyond the apex of abdomen. Pentandrce. 



3 (2) Cerci short, not much more than four times longer than broad, 



scarcely projecting beyond the apex of abdomen. Flavipes. 

 VOL. II. 14 



