BRENTHIS PALES, ITS HISTORY AND ITS NAMED FORMS. 231 



must be isifi ; says that Elwes considers that the possibility that arsi- 

 lache may be a true species, is not yet excluded ; says Elwes remarks 

 that caucasica most resembles the pale:^ form of the Pyrenees, but the 

 underside is more strongly spotted, and stands midway between pales 

 and arsLlache : says that cjraeca in its underside and fringe characteris- 

 tics agrees with many Alpine and Himalayan specimens. 



Euhl is doubtful whether isis ^ , which is distinguished by larger 

 size, is to be held as other than pales. The 2 isis is easily distinguished 

 from pales by its far darker upperside, but doubtfully from napaea, since 

 both varieties run into one another. In a large mass of material there 

 are many intermediates, and the distinction between isis and napaea 

 does not stand. He considered that lapponica forms a transition to 

 arsilache. He put var. arsilache, Esp. = ««/»«<?«, J)\rg. = pales, 0. He 

 made cancasica, StQ!;i'. = arsilache, H.S. 



On the whole, Eiihl's remarks emphasise the necessity of collating 

 all the named forms from the type localities, if it be possible, before the 

 really true significance of the various names can be ascertained. With 

 a species which occurs in very large numbers in its habitats over such 

 a vast area of the two continents, there arises every possible grade of 

 intermediate form, a fact which makes it the more difficult to be sure 

 that a particular locality is the geographical area where a particular 

 form is the dominant one. 



In 1899 Moore, Lep. Ind, vol. iv., p. 244, pi. 375, figs. 2, 2a, 2d, 

 gave an account and description of sipora. This description does for 

 pales quite well as a general view, and the figures support this view. 

 Tbey represent forms which in shape, colour, and markings, both ^ 

 and 5 are essentially pales of the Alps. 



On page 245 Moore redescribed Staudinger's (jenerator. He stated 

 that it difiers from pales and sipora in that the forewing is mors sub- 

 triangular in shape, the costa more arched, the outer margin curved 

 and less oblique, with markings as in the usual pales forms. On the 

 underside the discal markings are obsolete in the forewing, which is 

 pale fulvous in ground colour. The ground colour of the hindwing is 

 yellowish, with marginalpale olive-brown markings similarly disposed 

 as in pales. The pearly-white spotting is well developed. The figures 

 are larger and somewhat pale in ground, while the underside of the 

 hindwing shows less tesselation of the shades of colour. 



Lambillio«, in 1900 in Cat. Lep. Belg.. p. 9, included var. arsilache 

 in the list of Belgian Lepidoptera, but expressly states that the type 

 does not occur. 



In the Ent. News, vol. xi., p. 383 (1900), Dr. Holland described a 

 Brenthid, which came from the mountains of Alaska, as Brenthis pales 

 var. alaskeiisis, from a single example. He says that the underside is 

 '• much as in typical pales," but " it differs widely upon the upper 

 surface." It seems nearest to Staudinger's var. ijenerator of the Trans- 

 altai. " The fuscous area of the tarsal portion of the primaries and 

 secondaries is reduced, extending outwardly only to the middle of the 

 cell, and the entire wing beyond this is bright reddish fulvous, with 

 the characteristic lines and spots narrow and fine." 



Galvagni, in 1900, Verh. z-b. Ges., Wieii., vol. 52, p. 565, 2 figs., in 

 a paper on the Lepidoptera of the Brenner district, gave an extended 

 account of the variation of B. pales, including descriptions of three 



