Types.—Two females (imperfect and not completely mature), 12 larval cells and 26 infested twigs. Holotype female and galls in the collections of The American Museum of Natural History; paratype female and galls with the author; galls at Leland Stanford University and the U. S. National Museum. Labelled Ashland, Oregon; April 6, 1920; Q. Kelloggii; Kinsey collector.
This is a very common cynipid throughout the Pacific Coast region, its presence being made noticeable because the leading shoots and ultimately the whole tree may be killed. I have seen small stands of young black oaks, possibly fifteen years old, almost completely killed out in this way. It has, however, been difficult to obtain the wasp, apparently because the larval cells fall out of the twigs before maturity; possibly the insect completes development and emerges only after it has been on the ground for some tinme. From galls collected from January through April no adults were obtained, and only two individuals which had failed to quite complete development were cut out of the few larval cells remaining in the twigs. A very similar if not specifically identical gall is found on Quercus Wislizeni.
Andricus perfoveatus, new species
Plate XXIV, Figure 8
Female.—Antennæ wholly deep brown, 15-jointed; median groove distinct, scutellum roughly sculptured; mesopleuræ with a large aciculate area; cubitus continuous to basalis; tarsal claws simple. Head: About as wide as the thorax; hardly widened behind eyes; black, mandibles rufous brown; roughly coriaceous-rugose, rugose and somewhat hairy on the face. Antennæ densely hairy; the third joint not much longer than the fourth, the fifteenth not much shorter than the fourteenth. Thorax: Entirely black; mesonotum roughly coriaceous, almost naked of hairs; parapsidal grooves distinct, wider posteriorly, continuous to the pronotum where they diverge sharply, moderately convergent at the scutellum where they are much broader; median groove wide at the scutellum, distinct for less than half the length of the mesothorax, but indicated by a slightly rugose depression anteriorly; anterior parallel lines scarcely indicated; lateral lines indicated only by a smoother area; scutellum much longer than wide, roughly but not deeply sculptured, with the two large, deep, shining foveæ at the base somewhat sculptured, and separated by rougher sculpturing; metanotum hairy only at the sides; pronotum roughly aciculate or sculptured laterally, sparsely hairy only on the edge; mesopleurae almost smooth and shining, very sparsely hairy, with a large, central, aciculate area. Abdomen: Piceous to black,
lightest ventrally, entirely smooth and shining, very scatteringly hairy laterobasally, on the posterior edge, and on the ventral spine and valves; about as wide as long, produced dorsally, the ventral edges of segments two to four well rounded, the hypopygium somewhat produced, the valves at about a 60° angle, second segment occupying about half the abdominal area. Legs: Somewhat hairy, yellow-brown, the coxæ, trochanters, and tips of tarsi dark brown; tarsal claws simple Wings: Clear, finely hairy, ciliate, veins deep brown; areolet moderately small; cubitus reaching the basalis; radial cell open; second abscissa of radius not quite straight,