rearpittdatonj oditudes in Lcpidopteiv. 313 



in tho diviim (Initteiily) altitude only twelve minutes, and 

 Avere then i>laeed in tlie tieonietrid (ileltoid) position. Heing 

 disturlied some tive minutes later, so that it rail two ineiies, 

 it settled apaiii in the same attitude. The two oostae form 

 an angle of ab(^)ut 10(V'; an hour later it was about 150"\ 

 and in aniUher hour the usual resting position was attained, 

 with costal angle of IW to 2(H)'\ /. c. with the wings forward 

 of having the eostae in line. 



Sch'iiio ill list raria. This species dithers a good deal fnun 

 <S. ilhnxiiia in its metlnxls of proceeding from wing expan- 

 sion to the normal resting position. Though in a warm 

 rocun. specimens would occasionally be more than half 

 an hour after emergence before any sign of the wings 

 expanding could be detected. The wings then expanded 

 rather rapidly, taking, however, usually about or a little 

 over thirty-five minutes to expand. When expansion is 

 completed the wings hang backwai'ds. but only the tips of 

 the fore-wings touch each other, not indeed always doing 

 so. Then gradually the wings approximate to the butter- 

 fly attitude, that is. closely pressed together dorsally, so 

 that the eostae are coincident for their distal halves. 



The moth selects a vertical or. if possible, a shghtly 

 overhanging position in which to expand, so that now they 

 hang dowviwards, more or less, whilst in this backward 

 position. A special feature is that this doi^sal position is 

 gradually attained by quite imperceptible movement, and 

 this peculiarity continues throughout the whole evolution 

 from the beginning of expansion to the attainment of the 

 normal resting position; there is no sudden movement as 

 is so common, either of throwing the wings back, or assum- 

 ing the resting position. This closing backwards is attained 

 in ten or fifteen minutes after expansion is completed ; the 

 wings are kept so for about twenty n\inutes and then are 

 gradually separated in a minute or two till the costa of 

 fore-wings are separated to an angle of 10'' or \^f : the 

 .separating movement is continued in the same gradual, 

 hardly noticeable manner, till in about two more minutes 

 the angle is GC^, in two more 90'\ and in two or three more 

 finally 1(X>''^ or 110'"\ Usually the process is rather slower, 

 and varies a good deal in its rapidity at difTterent stages. 

 In the position of the moth, gravity no doubt tends to 

 make the wings hang directly backwards; nevertheless, the 

 position of the wings at this stage is with the eostae of 

 the anterior winijs at an auiile with each other of about 



