130 THE SILVER Y MOTE. 



appearing at the end of spring and the beginning 

 of autumn. 



Our next example is the SILVER Y MOTH 

 (Plusia gamma), so called on account of the 

 peculiar white mark on the upper wings, which 

 looks much like the English letter Y or the 

 Greek letter y. Several of the Moths belonging 

 to this genus are remarkable for the letter-like 



Silver Y Moth. 



marks upon the upper wings. There is, for 

 example, the Plusia iota, in which the burnished 

 gold mark is something like the written letter i, 

 with its dot. There is also the Plusia Nu, in 

 which the mark is like the letter n written in silver 

 upon the dull grey of the wing, and the Plusia 

 terrogationis, in which the silvery mark, with 

 its neighbouring dot, resembles in some speci- 

 mens a note of interrogation. 



The colour of the upper wings is shining grey, 



