112 THE CANADIAN ENTOMOLOGIST. 



yet been reared, and these minute creatures will be found, no doubt, like 

 other and larger ones that live over winter in the galls, to be only of one 

 sex. The description is as follows : 



Head, thorax and abdomen shining black and smooth. Ocelli large, 

 but not conspicuous. Antennje 13-jointed ; ist and 2nd joints compara- 

 tively stout, the 3rd a little longer than the two preceding ones taken 

 together, very slender ; the remaining ones also slender, but slightly in- 

 creasing in thickness towards the last ; color, a pale, dusky yellowish 

 brown. Thorax without lines or grooves of any kind, anteriorly high and 

 rounded. Scutellum very small. Fovse obsolete. Legs dark brown, 

 except the joints and the tarsi, which are almost colorless. The wings 

 rather large. Areolet large. Radial area long, narrow and open. The 

 cubitus is very slender, and disappears at some distance from the ist 

 transverse. The vein bounding the areolet on the posterior side is so 

 nearly colorless at that point that the areolet itself might easily be pro- 

 nounced wanting. 



Abdomen smooth and shining ; the terminal segments, in dry speci- 

 mens, are almost entirely retracted into the rather large ist segment ; the 

 abdomen is sub-petiolate. 



Length — body between. 04 and .05, wing. 06, antennae .03. 



C. Coxii, n. sp. 



Galls : Hard, smooth, woody knots or swellmgs on the twigs of 

 QuercHS, sp. They are covered with bark not unlike thi rest of the twig. 

 The two specimens in my collection are not more than three-fourths of an 

 inch in diameter, but whether of average size or not I am unable to say 

 They might easily be taken for small specimens of C. Siittonii, j5, from 

 California, or for C. batatoides, Ashmead, an unpublished species from 

 the live oaks of Florida, but the insects differ specifically from both these. 



My specimens were received from Prof E. T. Cox, who collected 

 them near Tucson, Arizona, probably from one of the dwarf live oaks of 

 that region. I have reared from them only female gall flies, which are 

 described as follows : 



Head deep yellowish brown ; vertex very slightly punctate. Ocelli 

 small, black. Antennae near together, 14-jointed ; ist joint short club- 

 shaped, 2nd short ovate ; these two, in a favorable light, are an almost 

 golden yellow ; 3rd one-third longer, and the 4th a little shorter tlian the 

 ist and 2nd taken together; the 5th, 6th and 7th short, and the remain- 



