It is quite evident that this species has been wrongly identified in most collections owing to the fact that Williston erroneously placed his C. obscuripennis as a synonynl of brachyrhynchus. In Williston's table of species (Trans. Con. Acad. Sci., vi, 390) obscuripennis goes into couplet 2 under the caption: “Third joint of the antennae distinctly shorter than the second.”