IDALUS. By Dr. A. Seitz. 
347 
P. optimus Btlr. (44 k). Thorax and forewings traversed by a violettish-brown network in such a optimus. 
way that there remain numerous honey-coloured cells pupilled scarlet. Abdomen darker, hindwings lighter 
rosy-red. In the typical form from the Amazon the network is rather uniform; only obliquely before the apex 
and above the proximal margin there extend somewhat thicker cords. — In intensa Rothsch. (44 k) these latter interna. 
two cords are about 2 or 3 times as thick as in specimens from the Amazon; from Guiana. — In similis Rothsch. similis. 
(44 k) the network is twisted somewhat differently, the intermediate threads more distinct, the hindwings 
lighter; Guiana and Amazon. — attinis Rothsch. (44 k) shows yet 2 dark clouds before and behind the middle affinis. 
of the costa; from Brazil and Peru, — and ockendeni Rothsch. (44 k) is the same, though larger; it shows besides ockendeni. 
brown marginal spotting below the apex and has whitish instead of purple-pink hindwings; from Peru. — 
It seems to me to be doubtful whether all these forms can be considered as species, as was assumed. The butter¬ 
flies are in some places common. 
P. hieroglyphica Schs. (44 k) is coloured like the preceding, but the net-work consists more of straight, hierogly- 
brown lines cutting the dark veins, than of undulate or dentate bands; at the base of the proximal margin a phica 
large, oval, red spot. French Guiana. Known to me from the description and the figure in Hampson’s Catalogue 
copied here. 
P. ignipicta Hmps. (44 k). Thorax and forewings violettish-brown, collar as well as spots at the base ignipicta. 
and proximal margin reddish-yellow; hindwings light pink, abdomen purple-red. From the Tijuca near Rio de 
Janeiro, certainly very rare, as it has not been found there by many collectors. 
P. nigranalis Schs. (44 k). Body quite yellowish-brown with a darker apex of the abdomen; forewings nigranalis. 
unicolorously chestnut-brown, hindwings light yellowish-brown. ,,South East Brazil”. 
P. jalapa Drc. (441). Unicolorously ochreous-yellow with lighter hindwings (except the margins); jalapa. 
in the $ the dorsum of the abdomen is posteriorly spotted reddish-yellow. Mexico. 
30. Genus: Idalus Wkr. 
Whilst the white Robinsonia, the red Melese, and the Bertholdia being decorated with a postmedian 
sparkling spot were very natural genera, in which there could at most only arise a doubt whether some were 
merely subgenera, we are opposed in this genus, in a similar way as in the Prumala, by a group exhibiting resem¬ 
blances to several other genera, its species having been described sometimes as Amaxia, sometimes as Automolis 
by Schaus, Lord Rothschild and others. We here also folloiv Hampson’s disposition applied in his excellent 
Catalogue and having since been chiefly adhered to by the other authors (Strand, Dyar). The genus, accor¬ 
dingly, comprises about 40 species, all of which are confined to Tropical America; no species reaches the United 
States; they preponderantly inhabit the hot parts of South America. The antennae may be doubly combed 
and also serrate dentate, and provided with ciliary tufts. The venation, as is often the case in the Arctiids, 
is little characteristic, particularly that of the hindwings varies rather considerably owing to the changes of 
its shape, scent-organs and distortions. The proboscis is always active, the head woolly haired, with short, 
erect palpi, the thorax densely haired like a fleece, the abdomen generally with glaring colours. On the forewing 
the anterior discocellular is entirely absent, the cell is of somewhat more than half the length of the costa and 
obliquely cut off; the 1st subcostal vein rises close before the cell-end; the venation of the hindwings is sometimes 
very much reduced by scent-organs. As to the larvae nothing has become known to me. The imagines mostly 
exhibit variegated, some even metallic colours, but they nevertheless seem to be decidedly nocturnal animals, 
since those that I chanced to observe, did not come to the light before 9 p. m. — The different groups of forms 
of the collective genus Idalus resemble in their habitus species of other genera, a fact often met with in the 
American region. Thus tetrodonta and affinis resemble Amaxia pyga (45 e); agastus and agricus the Automolis 
critheis and herois (49 k); J. xamhia resembles Automolis orbona (50 g), J. neja is like Amaxia pardalis (45 e), 
J. flavoplaga like Automolis per similis (51 h) and with the latter like Prumala flavoplagiata (44 g), and some 
of these resemblances may be founded on real affinities. Thus J. viridis Drc. I consider to be nothing else but 
a form of Chloroda rujoviridis (39 i) with distally paler hindwings. 
I. tetrodonta Dgn. (44 1). One of the largest and most beautiful Idalus. The purple-brown basal half tetrodonta. 
of the forewing, bordered by red, is obliquely defined towards the yellow distal part decorated with fine nebulous 
dots and with a characteristic, centrally strangulated apical spot. Hindwing white, anal third pink. Thus 
an assortment of colours is produced, often recurring in Tropical America, as we find e. g. in Neonerita syrissa 
(45 h), haemasticta, Epimolis zatrephica, Antaxia meridionalis etc. Venezuela. — In the form anodonta form, anodonta. 
nov. (44 1) from the Rio Songo in Bolivia the purple-violet basal area does not send any teeth into the yellow 
of the marginal half, the apical spot is more slender, the middle of the border of the hindwing sooty black, 
the under surface more yellow. A form very much like this is also before me from Colombia, from the Pacho. 
