142 TllK 15LTTEUFL1ES OF NEW ENGLAND. 



and Ihing grass-blades in C-auibridge for a fortnight or more and then were 

 gradually lost. One only seemed a little more aetive than the others and 

 ate slightly, as I thought, the tip of a cut blade of grass. The mature 

 cateq)illar may sometimes be foimd by day crawling upon the rocks, and 

 the late Mr. Sanborn told me that he once found one feeding by day on 

 Carex. But thougli, as already stated, I have repeatedly foimd the cater- 

 pillar by night feeding upon Carex, I have never found it by day ex- 

 cepting concealed under stones or crawling u[)on the rocks toward such 

 a concealment ; yet I have searched Carex and swept it with a net fifty 

 hours by day to one by night, and search by the lantern is neither so easy 

 nor so sure as by sunlight. I think therefore that its habit is to feed by 

 night — soon after dark is the best time for search — and conceal itself under 

 siu'face stones by day, generally on some flat or nearly horizontal surface. 

 They spin little or no silk and fall readily to the ground when disturbed. 

 They are very sluggish and coil themselves into half a ring when handled. 



Pupation. In the early part of July 18(39, the late Mr. F. G. Sanborn 

 searched very carefully f(^r the chrysalids of this species, spending ten or 

 twelve hours in raising movable surface stones, and in four or five cases 

 clearing away to the depth of several feet the smaller blocks of stone lying 

 in the "rock rivulets," as he appropriately terms the slight gulleys, wholly 

 without vegetation, which are scattered everywhere over the plateaus, and 

 which mark the course of the surface waters after rain : he succeeded in 

 securing only two living specimens ; nine others were either infested by 

 parasites, or were the empty shells of the previous year; they were all 

 found imbedded between the sides of the rock and the long, dense, crisp 

 moss surrounding it, between half an inch and an inch and a half below 

 the general surface, where the caterpillars had entered. They were not 

 attached to the rock or the moss, l)ut lay in horizontal oval cells, evidently 

 ormed by the movements of the cater[)illar before pu})ation : the most 

 particular examination revealed no trace of any web or silken thread even 

 as a lining of the cell. Mr. Sanborn's impressions, drawn mainly from a 

 comparison between the slender number of specimens he obtained and the 

 abundance of the butterfly, were that the healthier cater[)illars penetrate even 

 deeper into the ground ; but as I have also found pupae under or beside 

 surface-stones, and Mr. C. P. W^hitney has discovered larvae ready for their 

 change in similar localities, I am more disposed to believe that the place to 

 seek them is beneath and licside the uppermost stones and especially at the 

 edges of the "rock rivulets," where the vegetation is usually the freshest. 

 To one familiar with the locality — a surface almost completely strewn with 

 angular rock fragments, Mr. Sanborn's exploration will seem to have been 

 a very successful one. 



I leave the above paragrai>h as I ;Vvrote it fifteen years ago ; but I have 

 since spent two or three times as many hours as my eager friend, often with 



