INSECTS : WINGS AND THEIR APPENDAGES. 



81 



of the entire scale is that of a battledore. The ribs are 

 rather few and coarse, and they have this peculiarity, that 

 each rib swells at intervals into rounded dilations, each 

 of which has a minute black point in its centre. In some 

 of these battledore scales there is, near the lower part 

 of the expansion, a crescent of minute pigment-grains. 



The silvery grey surface of the front wings of a common 

 moth, known as the Buff-tip {Pygcera bucepltala), is com- 

 posed of scales of unusual magnitude, and of a remarkable 

 form, their shape being that of an expanded fan, and being 

 quite distinguishable by the unassisted eye. The ribs are 

 very fine and numerous, and there are diverging lines of 

 pigment-grains running through the scale. 



Those of the Emperor Moth (Saticmia pavonia minor) 

 are likewise triangular in outline, and are remarkable for 

 being deeply notched at the end ; so deeply as to leave 

 projecting points (from two to five) as long as, or even 

 longer than, the undivided portions of the scale. 



In some species we find scales the 

 tips of which are furnished with a curi- 

 ous sort of fringe. This slide presents 

 several such in the midst of many of a 

 more ordinary shape and appearance. 

 The scales in question are straight, and 

 parallel-sided, rather narrow, with the 

 basal end rounded, and the terminal ex_ 

 tremity tapered abruptly to a point ; it 

 is on each slope of this point that the 

 fringe is arranged. The surface does 

 not appear to be elevated in ribs, but 

 smooth ; while the whole interior, except 

 a crescent around the foot-stalk, is filled 

 with pigment-grains, imparting a mottled 

 appearance. It is remarkable that all 

 the scales of this form have the foot- 

 stalk turned in under the expanse. The example which 



G 



FKIKGKD SCALB OF 

 PIEBIS. 



