FAMILY ARCTIIDiE. 229 



Arctia Isabella (Harris). Isabella Tiger-moth. 

 Antennae filiform, tawny yellow. Thorax tawny and brownish. Abdomen tawny, deeper 

 color beneath, and marked with three rows of black spots, about six or seven in each 

 row running upon the back and middle of the sides. Forewings tawny, and marked 

 with a few black scattering spots. Hindwings nearly transparent, slightly tawny, and 

 marked with six tawny spots. Legs black or dark brown. 

 I have found this moth in Williamstown, though it does not seem to be very common, 

 as only a few individuals arc taken by the different collectors here. The caterpillar, how- 

 ever, is common, and is frequently seen travelling across our paths in autumn, always 

 moving as if in great haste. It is brown, and thickly clothed with hairs of a uniform 

 length, stiff and short : the hairs are black on the first four and two last rings. On being 

 taken up or touched, it rolls itself up. It feeds upon sundry kinds of herbs, but it is not 

 to be ranked among the decidedly injurious insects. 



Arctia virginica. JMiite .Miller, or Virginia Ermine-moth. 

 Color white. Forewings marked with a black point, and two black dots on the hindwings. 

 Abdomen marked with three rows of black dots, one on the top of the head, the two 

 others upon the sides, between which there is a yellow stripe. Thighs of the forelegs 

 ochre-yellow. 



Arctly (var. of virgimca). 



The wings of this moth are entirely white, except that the hindwings have two black 

 dots upon the underside, and one at the base of the forewings. The abdomen is ochreous, 

 with the three rows of black dots, and a broad belt of ochre-yellow between. 



The Arctia figured on Plate xlv, fig. 4, may also be a variety of the virginica, but its 

 abdomen is white. 



Arctia virgo. American Tiger-moth. (Plate xli, figs. 3 & 4.) 



Wings deflexed : color pink-red, with two central triangular black spots ; spots above 

 and below, angular, oblong : near the posterior margin, a thick black mark extending 

 nearly its whole length ; outer margin bordered with a fine black line. There are 

 twelve black angular spots in each wing, the smallest upon the upper and outer angle. 

 Secondaries yellow and red : in the male, the black dots large, and arranged some- 

 what in the form of a triangle. The spots near the anterior margin have quite a small 

 one between them. The female has about nine black spots on the posterior and middle 

 half of the wing. 

 Caterpillar brown, with four yellow or yellowish white and green stripes, interrupted 

 with paler brown, upon each bulging ring, and ornamented with a double row of 

 round dots ; below which, upon the sides, there springs a heavy brush of brown hairs 

 arranged in a thick pencil. 



