THE CANADIAN KNTOMOLOGTST. 55 



not difficult to remove these tubes or larval cells from partially dried galls. 

 Their thin walls are formed of long straight woody tissue. In the basal 

 third of the tubes are the larval cells, one in each, and above the larva 

 is a thin paper-like partition so concave beneath as to form, with the sides 

 and bottom, an oblate spheroidal larval cell. Above the partition are a 

 few shreds of a pith-like substance that filled the entire tube while grow- 

 ing. The bark is all that offers serious hindrance to the egress of the 

 insect when mature. 



I have been thus particular in describing the structure of this gall 

 because several other species known to me have a structure somewhat 

 similar and I do not remember to have seen them described. 



Gall-flies : All females. Head black, and with the entire thorax cov- 

 ered with short appressed hairs. Vertex slightly rugose. Antennae dull 

 dark brown, 15-jointed; ist joint large, club-shaped; 2nd short, ovoid; 

 3rd a little longer than two preceding taken together ; 4th to the 9th each 

 slightly shorter than the preceding one; loth to 14th of nearly equal 

 length; 15th very short and small, but separated from the 14th by a v^ry 

 distinct suture. Face black, mandibles dark. Thorax with t\\'o short 

 smooth parallel lines, not grooves, which extend half way from the collare 

 to the scutellum, and two outside of these also parallel, which extend half 

 way from the scutellum to the collare ; also a smooth line over the base 

 of each wing. All these lines are smooth and entirely destitute of hairs, 

 and in certain lights they appear as slightly raised ridges, rather than as 

 furrows, as is the case in other species when the parapsidal lines are pre- 

 sent. Legs dark brown, nearly black, except the femur, which is a clear 

 shining brown. Ungues black. Wings hyaline, subcostal and first trans- 

 verse veins heavy, others slender, but distinctly defined ; all dark dusky 

 brown, almost black. Areolet large, cubitus very slender, in some cases 

 not quite reaching the first transverse. Radial area open and the radial 

 vein straight. 



Abdomen clear shining brown ; first segment in size equal to the three 

 following taken together. Microscopic hairs on this segment beneath the 

 wings. Sheath of the ovipositor dark brown and with the ventral valves, 

 has fine short hairs along the entire length, but no tuft of these at the 

 point of either, as in most species. 



Length : Body, .15, wing .20, antennse .08. 



I first received this species from Mr. William Sutton, of San Fran- 

 cisco, Cal., to whom I am also indebted for other interesting species of 



