No. 2368. AMERICAN SUBTERRANEAN GALLS ON OAK— WELD. 209 



Genus XYSTOTERAS Ashmead. 



13. XYSTOTERAS CONTORTA, new species. 



Plate 30, figs. 10, 11. 



Agamic female. — Abdomen and eyes black, rest of body tan, with 

 dorsal part of head and distal part of antennae infuscated. Head 

 broader than thorax, coriaceous, shining, face with setigerous punc- 

 tures, axial line 0.55 of transfacial, interocular area broader than 

 high, malar space about one-third eye and with groove, ocellocular 

 space longer then antennocular, antennae 13-segmented, first two 

 not stouter than rest, second as long as a fourth. 5-13 gradually 

 incrassated and bearing sense organs, last one and one-half times as 

 long as preceding. Mesoscutum smooth and polished without trace 

 of grooves, broader than long, concave on hind margin and united 

 to scutellum without trace of suture except laterally on scapulae. 

 Scutellum faintly coriaceous, with transverse groove at base in 

 which is a median depression, rounded behind. Propodeum without 

 carinae. Legs pale, hind tarsus shorter than tibia, second shorter 

 than fifth, claws with weak tooth. Wings hardly protruding beyond 

 tip of abdomen and here considered abbreviated but with complete 

 and distinct venation, first abscissa of radius angled and a cloud 

 from angle includes free part of subcosta, areolet complete, cubitus 

 reaching basal, surface pubescent and margin ciliate. Abdomen 

 compressed, broader than long, as long as head and thorax together, 

 second segment making about one-third, ventral spine very short, 

 ovipositor when dissected out one and four-tenths times antenna. 

 Using width of head as a base, the length of mesonotum ratio is 1.0; 

 antenna, 2.2; ovipositor, 3.1; wing, 2.4. 



Length of 6 pinned specimens, 1.7-1.8 mm. 



The only other described species in this genus is black, and the 

 wings hardly reach base of abdomen. If wings are considered normal, 

 it would run in the key to Neuroterus, to which it is not closely 

 related. 



Type.— Cat. No. 22585, U.S.N.M. Four cotypes. 



Host. — Quercus breviloba Sargent, Quercus stellata Wangenheim 



Gall. — Gnarled woody swellings at base of young sprouts which 

 are only a few millimeters in diameter. Covered with normal bark. 

 Polythalamous. 



Type locality. — Austin, Texas. Collected galls on Q. breviloba 

 October 30, 1917, both old galls and fresh ones with pupae in. Living 

 adults were cut out on December 12. Collected one gall on Q. 

 stellata at Palestine, Texas, October 16, 1917, and cut out one fly 

 December 1. 



21177— 21— Proc.N.M.vol.59 14 



