Small galls in the axils of the lateral veins of the leaflets. Above
marked by a light colored angular area 1-1½ mm. dia. Below a small mass
of tissue (the gall proper) fills the angle, covered by a fine close
pubescence. Chamber within of small diameter, irregular in shape. The
characteristic mites were definitely observed. They are white in color.
On some leaflets every angle made by the mid-vein branching into the
lateral ones was occupied by a gall. On _H. cordiformis_, in Athens
County, Ohio, August.
Type specimens at Ohio State University.