245 



body before making, and frequently uses tliem in the con- 

 struction of, its cocoon. 



On the Lilac and on Prinos verticillata you may find another 

 verv extraordinary caterpillar, whitish in the middle, brownish 

 at each end, sparingly clothed with a few hairs, havmg a big 

 hump on the top of the eleventh segment, and resting m an 

 oddly crooked attitude, or when disturbed wagging its head 

 violently from side to side. This creature grows to the length 

 of one and one fourth inches, or more. Before cold weather it 

 eats a burrow in the side of a dried branch, and retires withm 

 it where it remains unchanged all winter, and sometimes for 

 more than a whole year. Ordinarily, however, it transforms 

 to a beautiful six-spotted moth in June. This moth comes 

 near to the genus Thyatka, I believe, and I call it Thyatira ? 

 sexguttata. [See a letter from Harris to Doubleday, March 



24, 1849.] . . r. 7 .. 



The caterpillars of our fine butterflies, Limeyutis ±.p/iesti07i 



and iWsippus, will soon begin to make the little leafy cones 



of the bases of leaves upon willows and poplars, mto which 



they retire for protection during the winter, and m which they 



''remain unchanged till the following spring. 



HARRIS TO MISS MOUKIS. 



Cambridge, Oct. 29, 1850. 



Your No. 2, larva and moth, is the insect which I name 

 modonta ( Gluphisia ?} ulmL The moth, as well as the larva, 

 is subject to a good deal of variation. One character, however, 

 it retains (and this is visible in your specimens), namely, an 

 oval whitish spot near the base of the fore wings, more conspic- 

 uous in some lights than in others, but always discoverable 

 under a glass, by the whitish color of the scales on that spot 

 I have found this insect very difficult to raise to the wmged 



