HYMENOPTERA. 399 



cloud on the tips of its wings. Excepting in this respect, it 

 closely resembles the dark-colored variety of Cynips oncratus, 

 and very little exceeds it in size. 



One of our smallest gall-flies may be called Cynips seminator, 

 or the sower. She lays a great number of eggs in a ring-like 

 cluster around the small twigs of the white oak, and her punctures 

 are followed by the growth of a rough or shaggy reddish gall, as 

 large sometimes as a walnut. When this is ripe, it is like brittle 

 sponge in texture, and contains numerous little seed-like bodies, 

 adhering by one end around the sides of the central twig. These 

 seeming seeds have a thin and tough hull, of a yellowish white 

 color ; they are egg-shaped, pointed at one end, and are nearly 

 one eighth of an inch long. The gall-insects live singly, and un- 

 dergo their transformations, within these seeds ; after which, in 

 order to come out, they gnaw a small hole in the hull, and then 

 easily work their way through the spongy ball wherein they are 

 lodged. They are less than one tenth of an inch long, are almost 

 black, or of the color of pitch, highly polished, especially on 

 the abdomen, and their mouth, antennae, and legs are cinnamon- 

 colored. 



It has been observed that no tree in Europe yields so many 

 different kinds of galls as the oak. Those which I have de- 

 scribed are not all that are found on oaks in this country, and 

 they seem to be sufficiently distinct from the galls of European 

 oaks. 



Round, prickly galls, of a reddish color, and rather larger than 

 a pea, may often be seen on rose-bushes. Each of them con- 

 tains a single grub, and this in due time, turns to a gall-fly, which 

 may be called Cynips bicolo?-, the two-colored Cynips. Its head 

 and thorax are black, and rough with numerous little pits ; its 

 hind-body is polished, and, with the legs, of a brownish red col- 

 or. It is a large insect compared with the size of its gall, meas- 

 uring nearly one fifth of an inch in length, while the diameter of 

 its gall, not including the prickles, rarely exceeds three tenths of 

 an inch. 



Cynips dichlocerus, or the gall-fly with two-colored antennae, 

 is of a brownish red or cinnamon color, with four little longitudi- 

 nal grooves on the top of the thorax, the lower part of the an- 



