THE CANADIAN ENTOMOLOGIST. 99 



apsidal grooves closely convergent at the scutellum. Short line usually 

 present over the base of each wing, in this species wanting. A few scat- 

 tered hairs on the borders of the mesothorax, most abundant at the base 

 of the -wings, Scutellum rugose, hairy. Fovae large and shallow. Legs 

 a uniform reddish brown except the darker tips of the tarsi.- Wings hya- 

 line, veins fine and slender, dark brown. Areolet medium size, cubitus 

 very pale and sometimes quite disappearing before reaching the ist trans- 

 verse ; radial area open, broad and rather abruptly terminated by the 

 short curve of the radial vein. Abdomen shining blackish brown, lighter 

 on the venter. A few hairs on the sides of the first segment beneath the 

 wings. The ventral valve projects a little above the dorsum. 



Length, body .08, wing .11, antennae .07. 



Described from twenty-five specimens, all females. In my collection. 



Cynips POLiTA, n. sp. 



Galls round, monothalamous, found abundantly in midsummer on 

 both surfaces of the leaves of Qiiercus obtusiloba, at or near the summit of 

 young and thrifty shoots, from one to fifteen or twenty on a single leaf. 

 They are from one-fourth to three-fourths of an inch in diameter, and are 

 when grown in the shade of a paler green than the leaf, but when exposed 

 to the sun are red or brown. They are attached so slightly to the mid- 

 vein and its branches that their removal leaves little if any trace. The 

 shell is when dry extremely thin and brittle, and the single round larval 

 cell is kept in a central position by fine radiating and branching fibres 

 that extend to the outside shell. 



These galls resemble, except in their mode of attachment to the leaf, 

 those of C. singularis B., but the insects differ considerably. They are 

 also somewhat like those of C. inaiiis Harris, but are many times 

 smaller. The insects are fully mature in October, but remain in the galls 

 over winter. 



I received my specimens of this species from Mr. E. Potts, of Phila- 

 delphia, and from Mr. Thomas Annadown, of Glassboro, N. J., and Mr. 

 P. H. Uhler informs me that they are very abundant in southern New 

 Jersey and in some parts of Maryland. 



The shining and finely polished thorax and abdomen suggest the 

 specific name given to the insect. 



Gall flies : All females. Head apparently black, but in a strong light 

 it is seen to be a very dark reddish brown ; cheeks a shade lighter than 



