OF TIIK AMAZON VAI.LKY. 521 



iu'r\ uros wliicli traverse the disk of the same wing heing of a ycllowisli cohjiir instead of 

 bhiek. In the 9 the diseocelhdars and tlie terminal parts of the median hranehes are 

 accompanied by dusky streaks. It eaiinot be considered, however, otherwise tlian as a 

 local variety of J). JJero, which has the hyaline disks of the wini^s always clearer, and 

 the black borders more sharply defined than 1). Bhoeo. J). Dcro is peculiar to South-East 

 Brazil, and is not found in the Amazon region, where the local form I). Rhoi-o lakes its 

 place. I have seen specim(>ns of D. llJioeo also from the neii;hl)oarhoo(l of ]?ogota. New 

 Granada. It (lies in thinned parts of the forest in Ygaj/), or flooded districts, in the dry 

 season. The sp(>cies is always aceom])anied by the followini,^ D. JCpi/lero, to which it has 

 so close a general resemblance, that I always found it dillicult to distinguish one from the 

 other when on the wing. The two forms, liowevca', lia\e no \('ry close real relationship, 

 there being ])oints of difference in their structure, namely, in the sba))e and neuration 

 of the hind wings in the males. The constant companionship of the two species can 

 only be explained by th(^ social and gregarious instincts of the Ucl icon idee. 



2. 1)iuci;nna EriuKuo (Boisduval ]\IS.), n. sp. 



Expanse 2" 5". 6. Wings hyaline, a patch of bright yellow across the middle and 

 apical regions of the fore wini;' and the? basal half of the hind win^-. Fore wiiitj: 

 (iborc, with the margins blackish, a triangular spot on the bind ])art of the cell, near the 

 base, and a narrow lu'lt across the disco-cellulars, extending down tlie second median 

 braiu'h (and jjartly down the third) to the hind margin, also blackisli, the dark colour 

 on the [josterior margin extending (piite to the median nervure and its first liranch. 

 Beneath, the same, except tiiat there are two or three wliite specks at the tij) of the wing. 

 Iluid icing : above, with the margins blackish, the portion between the seeoml nuHlian 

 I)ranch and the aI)dominal edge very much broader; a narrow dusky belt from the costa 

 across the disco-cellulars to the bind margin, most frequently interrupt(Ml in th(> middle, 

 also blackish ; tlK> nervures across the basal part cle^ir liylit yellow. Beneath, the same, 

 except that the base of the costa has a stripe of orange-colonr, and that the tip has two, 

 ami the liind margin near the anal angle four, white specks. 



The hiiul wing is short and sulxpiadi-ate, the ajjcx beinn' siiarply truncated; tlu' lower 

 disco-cellular is angulated (with a reciUTcnt nervule) close to the juiu'tion oi" the lowei' 

 radial. The si)ecies varies in the bi'oad l)lack l)order, near the anal angle of the bind 

 wing, having a reddish sti'cak in the middle, through which shine the white marginal 

 sjiecks of thi> under surface. 



2. Very variable in colours. The following are the chiel' variations : — 



1. Same as the c?, exce])t that the broad anal black l)or(ler of the hind wing is of a 

 clear orange-r(Ml colour in the middle. 



2. The wiiu;' mneh snll'nsed w itii l)lackish. leaving two broad l)elts across the fori> w ini;-. 

 the basal part and a sub;ipical spot of the hind wing alone iiyaline ; tlu> apical l)ell oi' the 

 fore wing has a patch of light yellow, and the nei'vur(>s traversing the basal ])ai1 oC the 

 bind wing are reddish. 



GcneraDy distributed throughout the Amazon region, in thinned parts of the forest, 



\ A 2 



