264 QUARTERLY JOURNAL. 



the wheat-flies, but commonly fading, when preserved, to a flesh- 

 color or dull yellow ; the thorax brown or blackish above, its sides 

 dull yellow ; legs blackish except at their bases, and poisers of the 

 same hue ; wings dusky, with their nervures more distinctly marked 

 than in the wheat-flies. I would propose for this species a name 

 alluding to the contrast between the color of the thorax and of the 

 abdomen, in a dorsal view of the insect (Plate 5, fig. 3). 



Cecidomyia thoracica. Red : thorax above blackish-brown : legs 

 and poisers blackish : wings dusky. 

 Length 0-05. 



A much more abundant species, and very closely related to the 

 preceding, occurs from the last of July till the middle of September, 

 and perhaps later. Its legs are dusky, but not of so deep a tint as 

 those of the thoracica, from which, moreover, it is readily distin- 

 guished by having invariably a fulvous-brown or blackish spot at 

 the base of the abdomen on its upper side. The base and sides of 

 the thorax are of the same color with the abdomen, namely, red, or 

 in old specimens dull pale yellow ; the upper side, forward of the 

 scutel, being brown. This species (Plate 5, fig. 5), may be named 

 and characterized as follows : 



Cecidomyia tergata. Red : thorax anteriorly and spot at base of 

 tergum brown : wings, legs and poisers dusky. 

 Length about 0'06. 



Both the preceding appear to be quite distinct from any of the 

 European species that have been described. 



In closing this paper, I have to apologize to the editors and pa- 

 trons of the Journal for the delay which it has caused in the issue 

 of the present number. I trust the paper itself may be found suf- 

 ficiently acceptable to atone in some measure for this delay, its 

 completion having required an amount of time far exceeding what 

 I had anticipated. 



Note, The insect, Plate 3, fig. 2, of the first volume, the name 

 of which was omitted at that time, is the Purpuricenus humeralis 

 of Fabricius. 



Salem, N. Y. October 8, 1845. 



