REAERANGEMENT OF THE FABRICIAN GENUS COLIAS. 167 



species hitherto classed as CoUas resolve themselves into two 

 natural genera, and for this purpose I propose the founding of 

 a new genus. According to Mr. Kirby (I.e.), we find thisoa, Men., 

 placed between two species, each as generically distinct from it 

 (however similar they may be in coloration) as Jieldii, Men., and 

 aurora, Esp. 



In founding this new genus of Pierinae, I am not unmindful 

 of the fact that the old genus should be retained to include the 

 earlier species, and this I have done in retaining imUeno, Lin. 

 (Taun. Suecica,' p. 1041), in the genus Colias, and making 

 edusa, Fab., the type of my new genus. 



Eriocolias, gen. nov. 



Allied to Mrganostoma, Eeak. Male with a black or rufous- 

 black band on outer margins of primaries and secondaries, never 

 spotted as in the female, but often traversed along the nervures 

 by faint streaks of the ground colour ; having on the superior 

 surface of secondaries, between the costal and subcostal nervures, 

 a patch of modified scales of a smaller size, and much more 

 crowded than the surrounding ones, usually of the same ground 

 colour. Females similar to those of Colias proper. Type, edusa, 

 Fab. Other species which fall into this genus are : myrmidone, 

 Esp. ; Jieldii, Men. ; vaatierii, Guer. ; meadii, Edw. ; &c. 



After the separation of Eriocolias, it will be found that the 

 species of the old genus arrange naturally into two groups, which 

 may eventually be generically separated ; but as yet I fancy this 

 cannot be done satisfactorily till we know more of the local forms 

 of some of the more arctic species allied to pal/eno, pelidne, 

 philodice, and enrijtheme. I have varieties of eurytJienie, Bois., 

 smd 2)hilodice, Godt., which a^prosich pelidne, Bois., very closely; 

 and I have transitional varieties between eurytheme and keewaydin, 

 and eurytheme and ariadne, both varieties taken along with 

 eurytheme in the mountains of Nevada at 7000 feet altitude. 



The two groups into which Colias, Fab., resolve themselves 

 are : — 



I. Males having the bands as in Eriocolias, but the basal 

 patch of scales as found in Eriocolias being absent. Females 

 with a more or less complete row of spots situated in the inter- 

 nervular spaces along the border of primaries and secondaries, 

 but as the marginal fascia of secondaries is not usually so broad 

 as that on the primaries, the inner portions of the spots are 

 indistinct and suffused, except in abnormally dark varieties. 

 Type of this group is ehrysotheme, Esp. ; others in the group 

 being thisoa, Men. ; eurytheme, Bois. ; keewaydin, Edw. 



II. Males and females similarly marked, the black fascia on 

 all wings spotted, but rather more regularly than in the females 

 of group I. Type, phicomene, Esp. Others in the section are — 

 hyale, Lin. ; paUeno, Lin. 



p2 



