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 the first segment (with the exception of the brownish black base), the second, and the third segments more or less light brown. The mesonotum of the female is entirely smooth and shining, while that of the male appears at times feebly punctate at the very anterior end, or at times finely roughened on the disk. The two parapsidal grooves are strongly convergent posteriorly. The scutellum is longer than wide, bound at the base so the anterior edge appears somewhat bordered, the disk in the female being more feebly rugose than in the male. The legs red-rufous, the bases of the coxae, as well as the claws black, the trochanters, a small spot on the under side of the femora, and the tips of the hind tibiae rather blackish. The hyaline wings have clouded veins. The abdomen of the male is small, triangulate, and short-petiolate, that of the female almost sessile; the petiole and the very base of the first abdominal segment are light brown; the length is 2.0 to 2.5 mm.

Early in May one may find these pretty galls originating from buds on old trunks of the oak or more rarely on the younger stems of the previous year's growth, sometimes singly, sometimes in large clusters. They are more or less egg-shaped and are succulent, but with a certain hardness. The epidermis is thickly covered with velvety hairs which are strikingly red when young, becoming dark violet when mature; the epidermis under a microscope appears covered with warty papillae every one of which supports a straight or slightly curled hair. The hairs are colorless and have the violet coloring matter only inside. The galls attain a size of 3.5 mm. Their development is very rapid. They appear early in May and yet even before the middle of that month the wasp may emerge.

TYPES.—4 insects (2 badly damaged) in the Vienna Museum (acc. F. Maidl in litt.). From Germany, probably from Halle.

The present descriptions are based on the published descriptions cited in the bibliography and on galls which I have from Berlin, insects from Solingen (P. Eigen coll.), and a fine series of 75 insects which I have from Denmark (Hoffmeycr coll.).

INQUILINES. — Synergus gallae-pomiformis (Fonscolombe). Emerges in June of the same year (acc. Dalla Torre and Kieffer 1910).

S. thauviacerus (Dalman). Emerges June 1 (acc. Wachtl 1876).

PARASITES.—Eutelus erichsonii (Ratzeburg) (= Platymesopus erichsoni). Emerges the same June (acc. Wachtl 1876).

E. tibialis (Westwood) (= Platymesopus westwoodi Ratzeburg). Emerges the same June (acc. Wachtl 1876).

Pteroinalus sp. Emerges the same June (acc. Wachtl 1876).

Torymus sp. Emerges the same August (acc. Wachtl 1876).

This is the best known of the bisexual forms of Cynips. Even tho the gall is so small that it often escapes attention, the abundance of the agamic folii in Central Europe results in taschenbergi being well represented in the collections.