228 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



and shining, longer than high, slightly compressed, the second seg- 

 ment with patch of whitish hairs at base on either side, making up 

 three-fourths the length, the third making up almost all the rest. 

 Ventral spine twice as long as broad. Ovipositor when dissected out 

 a trifle longer than antenna. Ovarian eggs well developed, 0.14 mm. 

 long, and including pedicel, 0.76 mm. Using width of head in balsam 

 mount as a base, the length of wing ratio is 3.8-4.0; antenna, 1.7- 

 1.8; mesonotum, 1.45; ovipositor, 2.0-2.1. 



Range in length of 30 pinned specimens, 3.3-4.5 mm. Average, 

 3.8 mm. Median, 3.75 mm. 



Type.— Oat. No. 22564, U. S. N. M. Sixteen cotypes. 



Host. — Quercus bicolor Willdenow. 



Gall. — Ellipsoid, 4.5 by 5.5 mm., single or in small clusters on 

 the small roots just below surface of ground under the tree. Surface 

 smooth, brown. Monothalamous with a firm wall less than one-half 

 millimeter thick when mature, exit hole at end 2 mm. in diameter. 

 Immature galls lighter in color, fleshy, translucent white inside. 



Habitat. — Type locality, Wilmette, Illinois. Collected also at 

 Evanston and Winnetka, Illinois. 



Biology. — The galls probably take two years to develop, the larvae 

 transforming to adults the second autumn but not emerging from 

 the galls until the following spring between April 15 and May 7. 

 They are all females. They oviposit at once in the swelling buds 

 of the same tree, but the alternating sexual generation is unknown. 



28. CALLIRHYTIS ELLIPTICA, new species. 



Plate 35, fig. 26. 



Agamic female. — Head reddish brown, abdomen brighter red, an- 

 tennae, legs, and thorax honey-yellow with the more heavily chiti- 

 nized parts reddish. Head rugose, as broad as thorax, widened be- 

 hind eyes, pubescent on face, clypeus almost circular with two deep 

 impressions at insertion, malar space about 0.4 eye, interocular space 

 about one and one-fourth times as broad as high, antennocular and 

 ocellocular spaces equal, palpi 4- and 3-segmented, mandibles 2- 

 toothed, antennae 1 3-segmented, first and third equal, fifth half as 

 long as third, fifth to twelfth subequal, last not quite one and one- 

 half times preceding, or 14-segmented, with last two subequal. 

 Sides of pronotum rugose. Mesoscutum a trifle broader than long, 

 surface pebbled with a tendency to become rugose on front and 

 along the parapsides which are obliterated in front, anterior parallel 

 grooves rugose extending back over half way, smoother lines over 

 base of wings, a shallow rugose streak makes an indistinct incomplete 

 median. Scutellum very rugose, with two rugose, sometimes com- 

 municating pits at base and impressed areas at sides, pits open be- 

 hind. Propodeum with two outwardly bent ridges inclosing a reti- 



