868 THE AMERICAN NATURALIST.  [Vor. XXXIX. 
Origin of 16 anterior veins obsolete. 
Origin of 6 anterior veins very indistinct, probably obsolete. 
Origin of 4 anterior veins indistinct, probably not obsolete. 
Origin of 9 anterior veins distinct. 
These results do not agree with Walsh's statement but, on 
the contrary, show that this feature of the wing venation cannot 
be taken as a specific characteristic. Wings of five C. s. 
gnaphaloides Walsh and two C. s. strobiliscus Walsh have the 
origin of the anterior branch 
very distinct. Four C. s. rho- 
Ras doides Walsh show it “ occa- 
sionally obsolete” as given by 
Walsh. The fact that varia- 
tions do occur and that each 
of the so called species has 
some individuals with the 
venation like that of other 
Fic. 4.— Wing venation of gall gnat. Cw,, Ante- species is sufficient to throw 
rior branch of cubitus. I. Origin distinct II. : A. 
Origin obsolete. this out as a determining char- 
acteristic. Walsh says him- 
self that the imagoes of his gnaphaloides and rhodoides are 
indistinguishable except for size, and I have shown that this 
difference is not fixed. 
His drassicoides differs from the others in having dusky 
instead of whitish thoracic hairs. 
have had showed this same difference, it is necessary, at least 
until other material is available, to let C. &rasszcoides stand as a 
distinct species. But from the data I have given and from the 
comparison I have made of Walsh's descriptions with each other 
ps with my specimens, I must conclude that strobiloides, strobi- 
liscus, gnaphaloides, and rhodoides are synonymous. Since the 
first name was given by Osten Sacken in 1861, I have taken it 
as the name of the species and the three others as synonyms. 
So the gnat which produces the four galls, Salicis strobiloides, 
— Strobiliscus, Salicis &naphaleides, and Salicis rhodoides 
Sua aieo 0:57 TAB verifies the inference of 
ue -Ow that Walsh’s species are all strobzloides. 
Summarizing, Khabdophaga strobiloides O. S. produces : gall 
R, 

Since the few specimens I 
