1865.] 353 



under side. This species probably belongs to the genus Teras Hartig, 

 now united to Andricus. (Compare also the following species). 



13. C. forticornis Walsh, Proc. etc. II, p. 4911 ( 9 ; Q. alba), is 

 easily distinguished from the preceding species by its smaller size, the 

 more uniformly reddish coloring of the head and the thorax, and 

 especially by the structure of the antennae, which are shorter and 

 stouter, whereas they are slender and filiform in the other species. 

 The third antenna] joint of 0. forticornis is not longer than the two 

 preceding taken together, obconical; the fourth is much shorter and 

 also somewhat obconical, and all the following joints, except the last, 

 are almost as broad as long. The third joint of 0. pezomachoides is 

 about once and a half the length of the two preceding taken together, 

 linear, slender ; the fourth, although shorter, has the same linear shape ; 

 the following joints (5, 6, 7) gradually diminish in length, but are all 

 elongated. This is also a Teras Hartig, and not Biorhiza Westw. 



14. C. hirta Bassett, Proc. etc. Ill, p. 688 ( 9 ; Q. montand) ; is 

 easily distinguished from the two preceding species by its large size, its 

 uniformly brown coloring and its pubescent abdomen. The structure 

 of its antenna) is like that of the antennae of C. pezomachoides 0. S. 

 (Compare also No. 43, below.) 



15. Philonixfulvicollis Fitch, Rep. II, No. 291; 16. Piiilonix 

 nigricollis Fitch, Rep. II, No. 292, which the author found on snow 

 in winter, but did not breed from galls, probably belong to Teras 

 Hartig. Whether 17. Biorhiza nigra Fitch, Rep. II, No. 290, is 

 really a Biorhiza, seems uncertain, but it is not improbable, as the Eu- 

 ropean species of this genus likewise occurs on snow. 



18. C. irregularis 0. S., Proc. etc. I, p. 65 ($ ; Q. obtusiloba) ; 

 19. C. MAJALIS Bassett, Proc. etc. III. p. 683 ( £ 9 ; Q. alba). Both 

 galls are exactly alike, as I have ascertained by comparison, only my 

 description applies to dry galls, Mr. Bassett's to fresh ones. Whether 

 the gall-flies have to be considered as distinct species or as phytophagic 

 varieties, I am uncertain, as I have never possessed more than a single 

 specimen (without abdomen) of C. irregularis. By all means this re- 

 semblance is close enough to render the description of C. majalis useful 

 to consult for the identification of my species, the abdomen of which, 

 as well as the female sex, have not been described by me. I have 

 already discussed above (p. 340) the generic location of these species. 



20. C. batatus Fitch, Rep. II, No. 311; Bassett. Proc. etc. Ill, p. 

 684 ( S 9; Q.alba); (about the generic location compare page 840, No. 

 4). Having received the gall and the fly from Mr. Bassett, I found, 

 upon comparison, that the gall is identical with the one I took for that 



