148 Journal New York Entomological Society. rvoi.xi. 



powdery frass at the bottom testified. A month later several very 

 delicate little pearly white moths made their appearance, and destroyed 

 my hope of an Adela, but as the habitat of this larva so closely resem- 

 bles that of an Adda larva, I have called it Adelalis, although to be 

 properly scientific I suppose it should be called in Latin the "Lichen- 

 feeding-^^/^A;-like-case-bearing-almost-invisible-pyralid." 



It is placed tentatively in the genus SympJiysa, as its structure more 

 nearly resembles the species of this genus than any other with which 

 I .am familiar, but there are certain differences in the moth as well as 

 entirely different habits of the larva; which will probably warrant the 

 erection of a new genus if nothing more closely allied than Symphysa 

 can be found to accommodate it. The case is from 14 to 16 mm. 

 long, 6 to 7 mm. wide, 2.5 mm. thick in the middle. It is composed 

 of small particles of nearly white lichen, held together with silk, the 

 outside appearance is rough very much resembling the lichen on a 

 fairly smooth piece of bark ; the inside is neatly lined with a thin 

 layer of white silk. 



The case is bivalvular, the under valve is only two thirds the length 

 of the upper, hence, at each end the latter overlaps the former, giving 

 a space for the larva to stretch head and two or three segments from 

 the closed case and feed in safety, entirely invisible, under the pro- 

 tection afforded by the projecting ends of the upper valve ; this item 

 of safety is further enhanced by the way the silk is spun into these 

 ends, causing them to lay with edges flat and pressed to the bark. 



The case is begun with a hinge on one side, exactly like a pair of 

 clam shells, and is enlarged by adding to the outer edges and ends. On 

 the under side the concentric rings of slightly different shades of 

 lichen clearly indicate this. In shape the main or protected part of 

 case is roughly oval, but with the extension pieces of the upper valve 

 broadening out equal to its greatest width. Fig. 20 on Plate IX was 

 drawn from an imperfect case, in perfect specimens the outer ends are 

 smoothly and evenly rounded. 



The larv^ spend from eight to ten days in pupa. On June 26 

 about a dozen moths had emerged, while a considerable number of 

 larvee had not pupated. Only one brood, the moths, no doubt, lay 

 their eggs shortly after emergence, and I believe the eggs hatch and 

 small cases are begun in the fall, the insects wintering in this stage. 



