182 PROCEEDINGS OF THE ACADEMY OF [Jan., 



it at all. At Prescott, Arizona (5,350 feet), 135 miles north of 

 Phoenix, strigosa flies in the company of plexippus from July to 

 September, the latter being the commoner of the two. D. strigosa 

 extends as far south as Galveston, Texas, and may also occur in some 

 parts of Mexico, near the northern boundary. Limenitis ohsoleta 

 does not occur at Prescott. 



The fine series of L. ohsoleta (hulsti) tabulated on p. 180 at once 

 made clear to me that the Arizona form is not, like fioridensis (eros) 

 in Florida, a local race of L. archippus transformed by mimicry of 

 the dominant local Danaine, but the bearer of an ancestral pattern 

 which preserves features lost by the two other mimetic races. I 

 therefore desire to correct my former conclusion, founded on the 

 figure of a single specimen, that ohsoleta is a modified form of archippus 

 (21, p. 460, 33, pp. 171-2). At the same time I remarked in the 

 latter paper (p. 172): "I have not yet had the opportunity of ascer- 

 taining whether this hypothesis is supported by evidence derived 

 from a careful study of the pattern." 



The hind wing. — The most prominent ancestral features of ohsoleta 

 are the traces of the white discal band derived from an ancestor with 

 a pattern like that of artheynis or weidemeyeri. In archippus and 

 fioridensis a trace of the white band is found on the under side of the 

 hind wing in some specimens, but so far as my experience goes never 

 on the upper surface. In ohsoleta some trace of it is always present 

 on both surfaces, but when, as in the majority of specimens, there 

 is a difference in the degree of development, it is stronger upon the 

 under side. It is more strongly developed in the females than the 

 males, and this is the general rule with the ancestral features of the 

 species, as it appears to be in archippus, of which a certain proportion 

 of the males in the Albany district, but no females, have entirely 

 lost the black discal stripe from the upper surface of the hind wing 

 (recorded by Mr. John H. Cook, 33, pp. 211-212). Thus the white 

 stripe, together with its black outer border, is evanescent on the upper 

 surface of the hind wing of 2 female ohsoleta from Phoenix and small 

 in the female from Tucson, whereas the same feature is evanescent 

 in half the males from Phoenix and but slightly developed in others. 

 The evanescent feature in both males and females is more strongly 

 represented, generally far more strongly, on the under surface. The 

 degree of development of the black band is generally related to that 

 of the white, the two being usually evanescent together or well 

 developed together, but the range of variation is much greater in the 

 white than in the black, corresponding with the entire disappearance 



