184 Mr. J. Havdy on the effects produced 



black with brown wings. During the present spring- I met with 

 one of these productions upon the Salix cinerea, tenanted by about 

 eight or nine pupae, which became flies on the 22nd of May, and 

 these were at once seen to be not all of one species. The smallest 

 and most numerous had the wings dusky and very pubescent, 

 with the antennse 17-jointed in the male and 16-jointed in the 

 female, and were from |-1 line long, and the expanse of the wings 

 2 lines. The second, of which I only obtained a single male, 

 was considerably larger, had the antennae 22-jointed, the winga 

 ample, clear, with only a few scattered hairs. Length 1^ line, 

 expanse of the wings 4 lines. I have not been able to identify 

 these with any described species, and have named the first C. sa- 

 ligna, and the second C Cinerearum*. The Cecidomyia salicina 

 of DeGeer, according to Macquart's account, has about twenty 

 joints in the antennse, and has the wings hairy and slightly ob- 

 scure. Length 2 lines. The woody oblong gall of the willow 

 likewise produces a Cecidomyia, which I venture to term C. Gal- 

 larum-Salicis. If I mistake not, from an examination of dried 

 specimens, the antennae are 20-jointed in the male and 19-jointed 

 in the female, and the wings are slightly dusky and grayish 

 pubescent. The length is 1| line, and the wings ai*e 3 lines in 

 expanse. Bouche, on the other hand, describes from this gall an 

 insect which he likewise designates Cecidomyia Salicina, as 1 line 

 long, with brown wings. There is thus a great confusion of 

 synonyms on this topic, and it is possible from the observations 

 which I have just recorded, that this may have arisen from in- 

 sects really distinct having passed under the review of different 

 observers. Mr. Westwood has recently bi'ought forward another 

 species found in the young twigs o£ Salix viminalis and /S". rubra. 

 This he names C. viminalis, and in it the antennae are 17-jointed 

 in both sexes, and the wings are colourless with the hinder mar- 

 gin strongly fringed. 



I have also recently remarked an instance of two species of 

 gall-midges acting in concert on roses. The leaflets of various 

 wild species of these are tenanted in the centre by companies of 

 larvae which cause this part to thicken and blister on each side 

 of the midrib, and the leaflet being thereby prevented from ex- 

 panding, protects, as if in a pod, the little community. These 

 larvae have the characters of those of the Cecidomyia, viz. are 

 spindle-shaped or subelhptical, only slightly convex, with distinct 

 subcompressed lateral margins, the head end attenuated to a 

 point, with a pair of horn-like bristles behind it, a dusky spot 

 visible above and beneath, and a dagger-shaped polished mark 



* Cinerea, a sectional term applied by Mr. Borrer to the sallows. 



