JULY. 203 



with a small transverse white line near the hinder margin 

 of the primary wings, and another towards the middle of the 

 secondary pair, forming two acute angles resembling the 

 letter W ; behind this, is a band of orange-red ; the margin 

 and the projecting tailed point are black, sometimes tipped 

 with white. The caterpillar is green, with three red spots 

 on each side of the lower segments, and a double series of 

 small dots on the back ; it feeds on the elm and blackthorn. 

 The perfect insect is in general rare, but in some seasons is 

 found in great profusion. 



Thecla pruni. Blach Hair-streak. This species has 

 often been confounded with the former, which is more com- 

 mon ; the difference on the upper surface seems to consist 

 in the addition of three or four crescent-shaped red marks 

 near the hinder margin; the colom- of the under side is 

 yellowish-brown, marked with an irregular silvery line near 

 the hinder margin of the primary wings, and across the 

 middle of the secondary pair ; behind this, is a row of black 

 spots, and on the margin a series of black crescents ; the 

 upper wings have the spots red. The caterpillar is green, 

 with longitudinal whitish rays, and numerous short trans- 

 verse lines ; the head is small and yellow. 



