80 JOUKNAL OF ENTOMOLOGY AND ZOOLOGY 



curve inward on the inner margin and are notclied on the outer, 

 and I make out also a third small pointed lobe a little distance 

 from these on either side. P. parvnla he says has no spine-like 

 plates, while I find three on each side in this." In the moults 

 the spines and lobes are lost. The shell glands are very small 

 and so hard to detect through even the high power of the 

 microscope that their positions are not as accurate as desired. 

 The circumgenital glands are very distinct and arranged in an 

 almost unbroken crescent anterior to the genital opening. The 

 number is variable — from twenty-one to thirty-three in two 

 individuals. In some individuals the body seginentation is very 

 distinct, while in others, as in Figure .3, D, there are no notice- 

 able divisions. From nine to thirteen segments have been 

 counted in various individuals. 



The females are usually found upon the bark of the previous 

 year's growth and upon the leaf petioles. They are so small 

 that one should first look for the roughened bark to locate an 

 infestation. 



YOUNG 



The young have not been obtained but cast skins of several 

 stages have been mounted with the other material. The 

 pygidium of one of these has been referred to above and is 

 illustrated in Figure 3, B. The antennje of several skins prove 

 to be six-articled as shown in Figure 3, C. 



MALES 



Scales — The exuvia; of the males are yellow and their position 

 is somewhat distant from the anterior end. The scales are little 

 more than fluffy, snow-white cocoons, made of fine white cottony 

 material which is arranged in an oblong cylindrical-like mass 

 and attached to the leaf and bark hairs of the host. There are 

 no visible carina^ or markings of any kind. Figure 2 is slightly 

 enlarged and shows these scales very well. They are very small, 

 being about 0.6 mm. long and 0.2 mm. wide, and are located on 

 the undersides of the leaves and u])on the younger twigs of 

 the oak. Though small they afford a ready means of locating 

 the scale. 



The adult males have not been observed. 



