99 



piece of wing under a compound microscope, when the trans- 

 parent scales will be seen overhanging the edge like shingles 

 upon a broken roof. Q eo . Dhnmock. 



(Read before the American Association for the Advancement of Science, at Detroit, 

 Mich., Aug. 14, 1875.) 



On the Insect Fauna of the White Mountains. 



In a paper published in the July number of Psyche, I drew 

 attention to some of the questions raised by studies on the in- 

 sects of Mount Washington. In concluding, I suggested the 

 probable identity of Agrotis opipara with A. islandica, and 

 Agrotis scropulana with Pachnobia earned. I am answered on 

 page 85 of this journal by the remark that " in making synony- 

 mical corrections, we want certainties, not probabilities." This 

 does not apply to myself, because I purposely made no synony- 

 rnical correction in these instances. As to my suggestions, 

 the first has proved itself correct. A specimen of Agrotis 

 islandica sent me by Mr. H. B. Moeschler, from Labrador, 

 cannot possibly be distinguished from my specimen of opipara 

 from Mount Washington. The markings are equally heavy 

 and distinct in both. I justify my remark "obviously unsafe ", 

 in the paper referred to, by pointing out that in Dr. Stauding- 

 er's original paper on A. islandica (Stett. Ent. Zeit., 1857, 

 p. 232), all the differences described on p. 85 of Psyche are 

 considered varietal of islandica. Staudinger says of islandica, 

 " This new Agrotis varies in size, still more in the markings, 

 but most of all in the color." Specimens are described with 

 unicolorously dark primaries, becoming almost smoky brown ; 

 this will account for the " gray " specimens differing from the 

 " cinereous " ones. I have Dr. Packard's Iceland specimens of 

 islandica, which formed the basis of Mr. Morrison's knowledge 

 of the species. They belong apparently to an inconspicuously 

 marked form, which seems to vary in color and depth of mark- 

 ing somewhat as velleripennis does. The structure is the same 

 in these specimens of islandica from Iceland and opipara from 

 Mount Washington ; the Labrador specimen might have been 

 taken on Mount Washington, and the Mount Washington in 

 Labrador, for all essential points of distinction between them. 



