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was not entirely completed, but it is believed that this difference in 

 color is not sexual. On comparison of the specimens the evenness 

 on the one hand, or in terspaceal scalloping on the other, of the inner 

 margin of the terminal band of the primaries will separate constantly 

 tetmis from diffinis, of which I have examined both sexes. I find 

 that the width of the band is a sexual feature, it being narrower in 

 the males of both species, and that it is also probably a compara- 

 tive feature to distinguish the species, it being narrower in tenuis 

 compared with the same sex of diffinis. The other chai'acters indi- 

 cated by me do not always hold good and are subservient to the char- 

 acters above given, and which I have primarily insisted upon in sep- 

 arating these species. Of these there is first the absence of the red 

 stain on the primaries at apices. In 9 $ specimens of tenuis com- 

 iiiunicated by Mr. Lintner, the stain is sometimes as prominent as 

 in diffinis, in bred specimens it is faint, and in Western specimens 

 it appears to be occasionally absent. As to the size again, some of 

 Mr. Lintner's specimens are hardly smaller than diffinis, while there 

 is a variation among them in this respect, and some Western and 

 bred specimens are as small as my types. Mr. Lintner suggests that 

 the apical stain becomes brighter by the abrasion of possibly darker 

 surface scales. Mr. Lintner writes : " The red becomes more appar- 

 ent with the partial denudation of the wing, it is scarcely apparent 

 in bred specimens and quite conspicuous in some beaten ones occa- 

 sionally extending half way along the margin at the cutting of the 

 nervules." There seems also to be a variation in the extension of the 

 sericeous paler vestiture of the thorax over the basal black segments 

 dorsally, perhaps sometimes due to the condition of the specimen. 

 All the species of this group have a thin covering of scales on the pel- 

 lucid fields of the wings on the escape from the pupa. Earely speci- 

 mens are captured which show traces of these scales. This statement 

 has been previously made by us of Haemorrhagia Bufaloensis (Ann. 

 N. Y. Lye. N. H.) and more generally of the entire group by Mr. Lint- 

 ner in his valuable Eeports. I am indebted to Mr. Lintner for an op- 

 portunity of comparing a specimen of Mr. Strecker's Macroglossa 

 fumosa. I regard it as an example of //. tenuis in which these frail 

 scales are adherent. The three specimens on which Mr. Strecker 

 based his determination were bred by Mr. 0. Mfeske from pupae 

 received from Racine, Wisconsin. The 5 differs in no wise from 



