130 



THE MICROSCOPE. 



Sept. 



two cast skins remain in an overlapping position on the 

 anterior portion of the scale. 



The male scale is much smaller than the female, as 

 indicated in the figures, and is otherwise distingnished 

 by a few structural peculiarites. In the first i)lace, there 

 is but one cast skin at its anterior extremity, and in the 

 next place, the hinder i)ortion of the scale is hinged in 



Mytilaspis i>omorum or Oystor Shell Bark lonse : a, femali' scale from beUiW showing eggs ; b, 

 same form above greatly enhirj^ed ; c, female scale<; d, main Hcale-eularged ; e, male scales on 

 twig — natnral size. 



such a way that it lifts up like a flap, permitting the escape 

 of the adult male. The different stages and structural 

 details of the insect are so well shown in the figure as to 

 require no further description. 



Scurfy Bark Louse. — This scale insect occurs abund- 

 antly upon apple and pear trees, also on quince, black- 

 cherry, currant and mountain ash, also on the Japan 



