Andricus marmoreus, new species

Gall. — A solid, marble-like gall, mottled in color, about globular, and smooth, with a blunt tip. Monothalamous. The gall is 9 mm. or less in diameter, subspherical, somewhat flattened vertically, with usually a broad-linear tip at the apex 2-3 mm. long; the surface is light brown, not entirely smooth in dried specimens, the deeper portions colored darker, forming a speckled or even mottled design. The gall is solid, although the tissue is not compact, and contains a distinct but not separable larval cell which is about 3 mm. in diameter. Often in numbers, though not densely clustered, on the new shoots of Quercus sp.; the wedge-shaped base of the gall is inserted in deep slits in the twig, causing thin layers of the bark to flare slightly around the base of the gall.

Range: San Luis, Potosi

The gall is like a typical "bullet-gall" of the genus Disholcaspis, except that it does not have a separable larval cell.