In a recent paper (1940, Trans. Roy. Soc. Can. Sec. V, 53) I emphasized the importance of the genitalia in determining species in Group A of the genus Coleophora, i. e. (according to Barasch) those species in which the aedeagus is strengthened with lateral rods of chitin. In this large group it will frequently be found that several species possess an almost identical type of maculation and cannot satisfactorily be separated on this character alone with any degree of certainty; the genitalia in both sexes, however, provide excellent means of separation.