In “The Bulletin of the Geo. Survey,” v. 3, p. 134, I have referred to two species or varieties of Batrachedra found by me in Colorado. Some of these specimens found at Colorado Springs I referred doubtfully to the European species B. præangusta. others found higher up the mountains I named B. Clemensella, stating, however, the doubt whether the two forms were really distinct. After the grerter portion of that paper was in the hands of the publisher, I received from Mr. Stainton two specimens of præangusta, by which I was enabled to recognise my B. Clemensella as a variety simply of that species, and to increase my doubts whether the supposed species were really distinct