(322 [December 



out any stria or vitta. Another 9 showed the same stria rather less deep and 

 acute, but without the normal sanguineous color being changed. Venter with 

 short, white or silvery white, more or less dense, appressed hairs. Oviduct + — ■ 

 IJt as long as the rest of the abdomen, almost always yellowish, but in 2 9 9 > 

 besides the one already i-eferred to, it was sanguineous, joints 1 — 7 of the abdo- 

 men being covered by brown hair except the sutures which were sanguineous, 

 and only the Sth or last being glabrous and entirely sanguineous, ie^.s (dried) 

 pale, with their tarsal tips and the whole of their superior surface, except more 

 or less of the basal part of the femur, usually coal-black, but varying all the 

 wav to the entire leg being pale and almost immaculate. Wings tinged with 

 dusky, from fine appressed, dusky pubescence. The costal vein very stout and 

 black, except in a few specimens where it is less so. The 1st longitudinal vein 

 generally indistinct and more or less confluent with the costal, occasionally 

 pretty distinct and plain. The cross-vein between the 1st and 2nd longitudinal 

 vein obsolete. The 2nd longitudinal vein perfectly straight at tijj, and reaching 

 the margin of the wing much before the tip, at a point i of the way from the 

 point where it attains it in Cecidomyla {Dipt. N. A. fig. 1. p. 174) to the point 

 where it attains it in Spaniocera (ibid fig. 6. p. 175), whereas in all the preceding 

 species it reaches it as in Cecidomyia {ibid fig. 1. p. 174.) Anterior branch of the 

 3rd longitudinal vein very distinct at its origin, and curved nearly as in C. s^ 

 batatas, but still more apparently a prolongation of the main vein, and with the 

 tip, as in that species, scarcely recurved. Length % 9 (dried) .04^.07 inch. 

 Length wing % 9 .OC— .09 inch. 



Described entirely from 1 !» % . 24 9 of the first or spring brood ; but 

 9 % and 9 of the second or autmunul brood offered no remarkable va- 

 riation. The first brood came out April i(» — 3Iay 14, and in prodigi- 

 ous numbers for several subseijuent weeks; the second brood came out 

 July 31 — September 11. This species, like C. -s. bafafm, preserves its 

 colors very tolerably in the dried specimen, even as regards the abdo- 

 men. From the description of the 9 abdomen given above, it is mani- 

 fest that its sanguineous color is due to the included eggs, even the 

 oviduct, which is almost always yellowish, being occasionally sanguine- 

 ous. The two white vittte on the thorax, from which the species takes 

 its name, occur also in the Gall-gnat C. .v. batatas and in the Guest 

 Gall-gnat C. orhitalis. Very much like a minute specimen of C. s. 

 batatas, but may be distinguished by its smaller size, by the S antennas 

 having at least 8 joints fewer, by their pedicels being twice as long, and 

 by the 2nd longitudinal vein reaching the margin of the wing further 

 from the tip. The best distinctive character, however, is found in the 

 pupa, which, as it ordinarily has no dense, spongy substance to work 

 its way out through, has short antennal horns, not thickened at tip as 



