62 DERCAS; GOLIAS. By J. Rober. 



The ?? are evenly light orange-yellow above, with orange-red middle spots also on the forewing, the under- 

 side being lighter than in the cf'cf. 



It is very difficult to separate correctly the Gonepteryx-species of the asjxisia-alchida-grouTp, which is 

 abundantly proved by Leech's entirely abortive attempt to do so (in Buttertlies from China, Japan and 

 Gorea). We shall therefore not maintain that our exposition is correct in all points. 



.21. Genus: Dercas Boisd. 



Though this genus is closel}' related to Gonepteri/x ^ it differs in appearance as well as in structure. 

 The most conspicuous characteristic is the shape of the forewing. the apex of which is not only acute, but 

 more or less strongly produced. The whole distal margin of the forewing is denticulate in verhuellii, while 

 in enara only the anterior portion bears short teeth; the distal margin of the hindwing of verhuellii is 

 produced into a tooth inthe middle, the inner angle being sharply angulate, the margin being simple in 

 enara. The cell of the forewing is short and very much widened, the 2. subcostal branching off exactly 

 at upper angle, the 4. subcostal terminating in the costal margin. The antennae are short, being only 

 gradually widened into a feeble, indistinct, obtuse club. The palpi are short, being densely scaled. — Of 

 the 3 species of this genus 2 occur in North India and Ghina, the third flying in Sumatra and Borneo. 



verhuellii. D. verhuellii Hoev. (= lycorias Doubl.) (27 e) occurs in North India and Ghina. The upperside is 



lemon-yellow in the cf, being paler in the ?; the apex brown, a middle spot and a submarginal band 

 reddish yeUow; hindwing with brown marginal dots. The underside is paler, both wings bearing an 

 elongate, pale-centred middle spot. 



enara. D. enara Swinh. {= olens Sfgr. i. 1. ?) (27 e) is common in Gentral and West Ghina , flying at 



moderate altitudes. It is a local form of the North Indian tvaUachii Doubl. (= urania Btlr., decipiens Nicev). 

 Apex of forewing acute, but hardly produced, the distal margin being anteriorly shghtly denticulate, smooth 

 behind. Upperside rich sulphur-yellow, deeper in tint towards the margins ; the costal portion of the brown 

 apical marking edged with ferruginous yellow, a stripe of the same colour extending as far as the 1. median 

 vein. Underside lighter, with pale-centred middle spot, small brownish speckles at costa of forewing, both 

 wings bearing a brownish line from the apex to the middle of the hindmargin and small irregular spots in 

 the basal area. 



22. Genus: Colias F. 



This genus is unmistakably characterized by its external appearance, and by the total absence of 

 the praecostal nervure, which character it shares only with the externally quite different genus Terias. The 

 butterflies are mostly of medium size, but some species are to be counted among the larger butterflies. Antenna 

 rather shoi-f, with the club gradually incrassate, but distinct. Apex of forewing rounded off; forewing with 

 4 subcostals, the 1. originating far proxiraally to the apex of cell; upper radial branching off from the 

 subcostal vein, therefore the upper discocellular absent. 



The main area inhabited by the genus is Gentral Asia, which is the home of the larger proportion 

 of the species. In North America, on the mountains of tropical South America, and in the plains of the 

 southern part of South America there occur several species, in Africa only two (subspecies of ednsa and 

 hyale), in Indo-Australia, however, apart from the Himalayas and the faunisticaUy similar Nijghiri Mts., there 

 does not fh' a single species. Some species extend far north (f. i. , C. hoothii as far as the 75"), and on 

 Tierra del Fuego one of the finest and largest species is found (imperiahs Btlr.). Some species occur in 

 two broods, but probabh' most species have only one brood. Sexual dimorphism is well developed in 

 several species, as well as dimorphism of the ??, this sex often appearing in a pale and in a bright yellow 

 or orange form. The butterflies are fast and untiring fliers. The cfcf of many species have as a secondary 

 character a small sharply defined sex-mark of thick chalky scaling situated at the costa on the upperside 

 of the hindwing. 



marcopolo. C. niarcopolo Gr.-Grsh. (25 a), from the South-Eastern Pamir, is one of the smaller species. Upper- 



side of (f pale sulphur-yellow, with a not very broad greyish black distal marginal band and a non- 

 conspicuous large yellow spot on the hindwing, but without black middle spot on the forewing. Underside 

 of forewing chrty yellow, with greyish green distal margin; hindwing darker greyish green, with whitish 

 middle spot. The ? is yolk-colour above and below, the distal marginal band being broader and havmg 

 the inner edge diffuse, the forewing bearing yellow submarginal spots. — The form with brighter yellow 

 upperside, narrower dark distal margins and a black middle spot on the forewing above and below, may 



nicolopolo. be named ab. (?) nicolopolo (25 a). 

 palaeno. C. palaeno L. {= philomene Hbn., lapponica Stcfr., werdandi H.-Sch.) (25a). Upperside of cf pale 



yeUow with blackish brown distal margins, pale-centred dark middle spot to the forewing and light middle 

 spot to the hindwing; fringes red. Underside of forewing pale yellow with white-centred dark middle spot, 

 the costal and distal edges being red; hindwing yellow, strongly dusted with fuscous, the large middle spot 

 being mother-of-pearl colour, and the fringes red. The ? has a white ground-colour above, the underside 



