A contribution to our knowledge of the Stylopidae. 249 
sides. Dorsal abdominal stripe usually quite dark in front and fading 
out posteriorly, sometimes obsolete. Genital pores distinctly visible 
externally. 
About a dozen males, numerous male pupae and over 80 females 
collected by Dr. Wm. M. WHEELER at Colebrook Connecticut, during 
the month of August, apparently belong to this species, although the 
males differ in some respects from Krirpy’s original description. The 
locality is nearly the same however, and there seems to be only one 
species occurring in the northern states. The wings agree well with 
KirBy’s description: ‘‘Alae cinereo, albide, margine crassiori, nervisque 
nigris”, which could not refer to either of our Texan species. 
KirBy gave no description of the female, and so far as I am 
aware, no one has since described this sex, although it has frequently 
been collected by entomologists. 
Embryology. 
The following embryological notes are based upon the examination 
of upwards of 80 females of Xenos peckii, containing eggs. Unfor- 
tunately all of the material was collected at nearly the same season 
of the year (July and August) and the majority of the eggs proved 
to be in the same stage of development. As the specimens were not 
intended for histological study at the time of their collection, they 
were simply dropped into 70°/, alcohol. In spite of this, preservation 
was remarkably good, and there was little difficulty in obtaining good 
preparations. The most suitable method was to make sections of an 
entire animal and then both eggs and internal anatomy could be 
studied on the same specimens. For staining I have found DELA- 
FIELD’s haematoxylin subsequently extracted with acid alcohol and 
then fixed with ammonia water to be preferable in most cases. Iron 
haematoxylin gives fine differentiation but the tendency it has to stain 
yolk black made it unfavorable in many respects, as these black 
blotches often conceal important structures. 
Oogenesis. 
The process of oogenesis in Xenos is very peculiar, departing in 
a very decided manner from what has previously been observed in 
any other insects. From the parasitic condition of the adult female 
one would naturally expect to find profound modifications in the re- 
productive processes, and examination at once justifies such surmises. 
As the process of oogenesis begins at an extremely early stage of 
