€a«aritni| mntamalajbt. 



Vol. XXXVIII. LONDON, MAY, 1906. No. 5 



STUDIES IN THE GENUS INCISALIA, 



BY JOHN H. COOK, ALBANY, N. Y. 



The genus Ificisalia was proposed by Minot in 1872, to separate 

 from the unwieldy genus TJiecla those small butterflies which, on a basis 

 of general similarity of structure in the imago, seemed to be most inti- 

 mately related to Hiibner's 7iiphon^ which stands as the type. 



Ten forms referable to this genus have been described, eight of which 

 must tentatively be regarded as good species. The augustifius of West- 

 wood is now sunk as a synonym of aiigustus (Kirby), and the arsace of 

 Boisduval and Le Conte is accorded varietal distinction under Godart's 

 irus. All the species are confined, as far as is known, to North America, 

 and with the exception oi Mossi (Hy. Edwards), hitherto reported only 

 from Vancouver Island, are found within the United States. 



Niphon enjoys the widest distribution, being found on both sides of 

 the continent, and, in the east, ranging from Canada to Georgia. 

 Augustus is apparently confined to the northern part of the eastern half of 

 the continent. It is abundant in Canada, and I have taken it as far south 

 as Maryland. Irus and Henrici have been confused so often that the 

 geographical distribution of neither is definitely determined. It may, 

 however, be confidently stated that the range of Hoirici is more restricted 

 than that of irus. The latter occurs in Georgia according to Abbot 

 (whence Henrici has not been reported) and is found along the Atlantic 

 Coast States as far north as Maine, and inland at least to Ohio and 

 Illinois. Lacking further definite information Dr. H. G. Dyar, in his 

 recent List of North American Lepidoptera,"^ gives as the habitat of 

 Henrici West Virginia only. This species has also been taken at Cincin- 

 nati, O. (Miss Braun), Rockland Co., N. Y. (F. E. Watson), Albany, N. Y. 

 (J. H. Cook), Schenectady, N. Y. (Harry Cook), and Franklin, Pa. (W. 

 T. Bell) t It doubtless occurs in other places, where it has been 

 overlooked by collectors or confounded with irus. 



*U. S. Xat. Mus. Bull., No. 52. 

 tPsyche, \'ol. 8, p. 143 (Xov., 1897). 



