THE CANADIAN ENTOMOLOGIST. 103 



Cynips affinis, n. sp. 



Monothalamous, round, thin-walled galls in the buds of Q/unus 

 prinoides, usually partly hidden in the scales of the bud, but in some 

 instances standing oui round and free like a little blister on the twig, in 

 size only large enough to hold the larva within, and in color dark brown 

 with grayish spots, or wholly brown. These galls are half-grown in the 

 autumn and develop so rapidly in the spring that the insects come out 

 just as the leaves begin to expand. 



I should have been disposed to consider this species a variety of C. 

 vesicula, which, both in gall and in insect, it closely resembles, had not 

 late discoveries shown that dimorphic species often in one generation 

 closely resemble each other and in the next develop characters that fully 

 establish their non-identity. 



The gall insects are of both sexes and may be described as follows : 



Female : Black. Head finely rugose. Ocelli prominent. Antenna 

 14 joints on a protuberant base ; ist joint short, truncated ; 2nd short, 

 ovoid; 3rd one-fourth longer than 1st and 2nd taken together, 4th equal 

 to the first two, 5th to loth gradually shorter, the remaining four sub- 

 equal, the last small and pointed. Color clear yellowish brown in the 

 basal half, changing to dusky brown toward the tip. 



Mesothorax very finely and evenly punctate ; parapsidal grooves 

 wanting. Scutellum small, punctate, separated from the mesothorax by a 

 rather broad shining groove. Legs clear, shining, almost translucent 

 brown, with a darker shade in the trochanter and upper half of the femur. 



Wings smoky. Veins smoky brown. Subcostal and the two transverse 

 much darker than the others. The areolet of medium size, and instead 

 of the usual equilateral, in this species it is an isosceles triangle with the 

 narrow base on the 2nd transverse vein. Cubitus slender but reaching 

 quite to the ist transverse. Radial area open, but the subcostal extends 

 above the base a short distance, and the anterior border of the wing is 

 somewhat thickened, which gives, in certain lights, the appearance of a 

 closed radial area. Abdomen briefly petiolate, black and shining, so 

 shrunken in the specimens before me as to render further description 

 impossible. 



Length, body .09, wings .11, antennae .08. 



Male : Antennae 15-jointed, slender, long, 3rd joint deeply incised. 

 Color of antennae as that of femajle. Wings much larger. Legs paler 



