Andricus perplexus, new species.

A small globular gall, somewhat pointed at apex and covered externally with an exceeding fine, short, grayish pubescence or bloom. Internally the larval cell occupies most of the gall. Diameter, 5 mm.

One specimen, reared November 21, 1877. The gall was found on the ground in O'Fallen Park, Missouri, in October, and the species of oak upon which it grows is unknown.