I SI A; ESTIGMENE; EUCHAETIAS. By Dr. A. Seitz. 
309 
2. Genus: Isia Wkr. 
The only species of this genus being better known by the name of Pyrrharctia Pack, is a very robust 
butterfly somewhat recalling the European Spilarctia lubricipeda L. ( lutea auct.) by its colouring and marking. 
The larva, however, deviates so much that the imago emerging from it, exhibiting besides more pointed wings, 
cannot be regarded as a Spilosoma or Diacrisia. The larva has on each of the 6th to 9th segments a dorsal 
brush, being otherwise peculiar of the Dasychira- or Orgyia- larvae, and on the 12th segment the dorsal hairs 
are prolonged. 
I. Isabella Sm. & Abb. (= californica Pack.) (39 d). Thorax and forewings yolk-coloured; hind- Isabella. 
wings in the $ lighter, in the $ in the distal part more reddish-yellow; abdomen reddish-yellow. Forewing 
often with small black dots and a loam-coloured shade, strewn either more sparsely or more densely. — Egg 
hemispherically, white, with a polygonical network noticeable only under the microscope. Larva anteriorly 
and posteriorly black, the 4 middle segments above haired more rusty-brown, each with a dense hair-brush 
on the dorsum. At the sides, above the stigmata, a light stripe, being broadly interrupted on each ring-inden¬ 
tation. On trees (cherry, oak) as well as on numerous low plants (Plantago, Solidago, Chenopodium, Compositae 
etc.). The authors figure the larvae on Elephantopus scaber. Pupa yellowish-brown, in a felt-like web. Every¬ 
where in the United States, in the east and west, from Canada to Texas, in summer common; the larva 
is particularly common in autumn, before hibernating, running across the roads. 
3. Genus: Ksti^ilieilC Hbn. (Leucarctia Pack.) 
This genus founded upon an Arctiid common in North America, comprises to-day about 30 species 
of a universal range. From the ver}^ closely allied genus Phissama (Vol. II, p. 90, Creatonotus, Vol. X, p. 252) 
it differs by the marks mentioned there. The thorax is so densely and uniformly haired, that in undamaged 
specimens neither the collar nor the shoulder-covers are particularly prominent. As far as they are known, 
the larvae seem also to be more finely haired. The genus is somewhat allied to the palearctic Diaphora. 
E. congrua Wkr. (39 e). $ very similar to the palearctic Diaphora mendica (Vol. II, t. 17 b), but congrua. 
often without any small black dots at all, or with but one at the cell-end of the forewing; A likewise entirely 
white, not grey as in mendica. Abdomen in both sexes snow-white —• In antigone Streck. (39 e) the forewings antigone. 
are more copiously dotted dark; — athena Streck. has a black instead of white antennal shaft, and prima Slosson athena. 
(39 e), presumably a distinct species, having beside numerous small spots on the forewings also small dorsal 
spots on the (yellow) abdomen. — Larva light grey with dark tubercles with bristly hair; the hair on the sides 
long; head of the young larva with 2 dark dots, later on black. On low plants. —- In the eastern parts 
of the United States, to the west as far as the Rocky Mountains. In the north (New England, Canada) 
the form prima is rare, in the south where the form antigone occurs, it is common in some parts. 
E. acraea Drury { — caprotina Drury, pseuderminea Peck, menthastrina Mart., californica Pack., acraea. 
packardii Schaupp) (39 e). Larger than the preceding, snow-white with small, fine, black, distinct spots and an 
orange-yellow abdomen spotted black, the with yolk-coloured hindwings, beneath quite yellow; but in the 
form mexicana Wkr. (39 e) also the <$ hindwings and under surface are white. — arizonensis Rothsch. is like mexicana. 
mexicana, but much more copiously and densely spotted black. — From the latter, Columbiana Rothsch. from cohnnbiana 
Colombia differs by the $ exhibiting only yet 2, the $ only few black spots at the margin and cell-end. —- alba alba. 
Rothsch. (39 e) from Central America is quite snow-white. —- In klagesi Ehrm. (39 f) the black spots of the klagesi. 
forewings have disappeared except faint traces. — dubia Wkr. (= rickseckeri Behr) shows sooty brownish dubia. 
body and wings. — Larva, when young, flesh-coloured, later on over the dorsum yellowish-brown with tufts 
of brownish bristles standing on the dorsum on dark tubercles, on the sides on reddish ones. Head lustrous 
black with yellow sutures. In the south particularly on rattlebox (Crotalaria) and other Papilionaceae, in the 
north common on Plantago and also many other low plants. The larva grows very stout. Pupa lustrous earth- 
coloured. Canada to Colombia. 
4. Genus : Kill'll JH‘t ias Lyman (Euchaetes auct.) 
Hereto belong about 15 species, slender, rather small butterflies with long forewings and short bodies, 
the $$ sometimes with anal wool. Proboscis absent, antennae doubly combed, the pinnae in the A not long; 
palpi short, rising obliquely; forewings without an accessory cell; the 1st subcostal vein rises immediately 
behind the middle of the cell, the 2nd before its end; discocellular of both wings slightly bent in, but not sharply 
angled as in Chloroda. The genus is exclusively American. 
E. oregonensis Stretch (39 e). Dull white, with a yellowish-grey hue over it. Head, anterior thorax oregonensis 
and abdomen yolk-coloured; the latter has black dots on the dorsum and sides. — Larva pale yellow, with 
light slate-coloured hair, that are particularly long at the anus. Canada and northern parts of the United States, 
