684 [December 



femur and tibia darker than the joints, tarsal tips black. Wings hyaline, 1st 

 transverse and radial veins dark brown, others pale but distinct; areolet of me- 

 dium size and at the base of the open radial area. Length .09. 



The '^ closely resembles the 9 in color and markings. The abdomen is very 

 lon^, and the antennae a rich amber color, with a few of the terminal joints of 

 a light brown. In all the specimens I have examined (16) the number of an- 

 tennal joints is sixteen. Length .08. 



Numerous $ $ and 25 S "S . 



Dr. Fitch has given a very correct figure and description of the gall 

 of his (J. q. bafatus, which, it will be seen, closely resembles that of the 

 above species. Indeed there is little or no apparent difference in the 

 galls more than pertains to the diiferent species of oak on which they 

 grow, but the flies are very distinct. As Dr. Fitch describes the fly so 

 very briefly that it may easily be confounded with C. q. scitula, 1 give 

 a more full description below: 



Quercus alba. 



C. q. batatus Fitch. (N. Y. Reports, Vol. 2nd. No. 311.) 



9 Black, shining, entire head black, vertex smooth; face, covered with a 

 fine thin pubescence; color of the palpi, clear vitreous brown. AntenncE 13- 

 jointed, first three joints pale yellow, others a pale semi-translucent brown. 

 Thorax black, shining, but under a powerful magnifier shows a net-work of fine 

 lines; parapsidal grooves and striae obsolete. Scutellum smooth, polished; a 

 few scattered hairs on the posterior portion; basal pits wanting; separated 

 from the mesothorax by a deep shining groove. Abdomen black and polished 

 but in all my dry specimens contracted and wrinkled. Feet, coxae clear yel- 

 lowish brown, femur, in the middle dark brown or black, as is also the tibia of 

 the posterior pair; remaining portions, except the tips of the tarsi which are 

 black, are of the same color as the coxse. Wings hyaline, all the veins dark 

 brown and of nearly equal size. The cubitus large and heavy its whole length ; 

 areolet large ; radial area open. Length .09. 



% . — The antennae of the male is ll-jointed. Feet dull pale yellow. Abdomen 

 petiolate by the elongation of the first segment. Length .08. 



Numerous specimens % and 9 •* 



*I am satisfied that there are annually two generations of C. q. batatus. The 

 first appears early in May, from galls of the preceding year's growth. — the last 

 late in .June, from green galls. I have often found perfect insects in the galls 

 in winter, and have reared flies from them, ajjparently of the same species 

 reared from the summer galls. Inquilinae in great numbers are produced from 

 the winter galls and few true gall flies, while the reverse is true of the summer 

 form. As many of the summer galls remain green after the flies have left them, 

 and as the tree's annual growth is nearly or quite complete the first of July, it 



