Mar. igoo.] DyAR : On LaRV^ OF THE GeNUS ArCTIA. 37 



kindly furnished me with in 1897. In the first stage the larva 'has 

 simple seta3, except on wart iii on joints 5 to 13 which bears two hairs, 

 no subprimary setae. The mature markings are outlined in stage II 

 when the warts appear, and the successsive moults disclose no striking 

 differences. I find the moths mate readily in the mating cage, the 

 male flying in during the night. 



It might be well to determine the number of larval stages under 

 varying conditions, and especially of the second or hibernating brood, 

 always giving the width of head for each stage. Otherwise the larvae 

 are fairly well known. 



Department of Agriculture numbers are 728P, 1045, 2451, 4117, 

 41 19 and 5865. 



5. Qiienselii is strictly an arctic species. It occurs in the cold 

 parts of both Europe and America, our nearest points being the sum- 

 mits of the White Mountains of New Hampshire. The moth has the 

 usual melanotic and blurred appearance of arctic forms and- the lining 

 of the veins varies considerably, so that, in my seven specimens, I 

 cannot always say that the median vein is broadly lined. However, 

 the species is distinct enough in appearance from all other common 

 forms. 



The larva is known from European material ; Hoffman figures it 

 black with pale dorsal line, the subventral hairs reddish. The only 

 American description is one by Dr. Packard of a " supposed " larva of 

 qiienscln, taken on the summit of Mt. Washington. I have had a 

 larva very like this from the same place, sent me by Mrs. Slosson in 

 1895 ; but I failed to breed it. As neither Dr. Packard's larva nor 

 mine correspond with the European qucnselii, and they are not un- 

 likely to belong to some other species, we must await the result of 

 positive breeding. 



Any of the members visiting the summit next season would do 

 well to search for qucnselii. It has been noted in Europe that the 

 moth appears only in every other year.'* The same may be the case 

 with us. 



6. Nais is on debatable ground. This and the two following 

 species are doubtfully distinct and often confused. It is not certain 

 whether we have three, two, or but one species. The matter is 

 further confused by wrong determinations and the larvre also are much 

 mixed as I shall proceed to show. I have before me 50 moths that I 



*Sandberg, Ent. Tidsk., IV, 16. 



