H. F. BASSETT. 313 



median lines and lines over the base-of the wings all present but not very dis- 

 tinct. The median lines reach about one-third the distance from the collare to 

 the, scutellum. The head and entire thorax have, to the naked eye, a dull ashy 

 red appearance. Scutellum small ; fovse widely separated, not smooth and shin- 

 ing. Abdomen black, very smooth ; first segment with a few scattered hairs on 

 its anterior half. Legs clear, semi-translucent red. Femur of the posterior pair 

 large in the middle, almost ovate. Ungues long, dark and slender. Wings 

 rather large, faintly fuscous; veins — the larger are very pale red, the smaller 

 almost or quite colorless. Radial area open, and by a slight incurve in the radial 

 vein the area is broadest in the middle. Areolet present, the anterior sides 

 bounded by very fine colorless veins. Cubitus short. Body .12, antenna? .09, 

 wings .15. 



This species differs from A. operatola Riley and Bassett in having 

 fourteen jointed antenna?, head and thorax darker red, smoother- 

 surface and a more dense hairiness or pubescence of the mesonotum. 

 The finer thoracic lines, the uupolished fovae and in the medium 

 sized but distinct areolet, also in the smaller size. All my speci- 

 mens are remarkably uniform in size and appearance. 



Andricus perditor n. sp. 



The acorns of Q. ilicifolia are, as is well known, two years in 

 reaching maturity. In the Spring of the second year they are still 

 very small, hardly as large as a coriander seed. At this time ants 

 are often seen hurrying about among the young acorns and feeding 

 upon a liquid that exudes from some of the acorns. The affected 

 acorns are really galls — transformed acorns— that differ little in 

 form and color from the unaffected acorns. The larva of a gall-fly 

 lives in each of these pseud acorns. Its larval growth is complete 

 in Spring or early Summer. I have never found them very abund- 

 ant though they appear quite constantly from year to year. I 

 have so far succeeded in rearing only a single gall-fly, and in this 

 specimen, cut from the gall, the wings are not fully expanded. 



This fly is a female and probably one of the agamous class whose 

 bisexual form is not yet discovered. 



Gall-fly. — Head, antennas and legs deep brownish red. The head finely punc- 

 tate. Mesothorax darker than the head and scutellum. Antennae fourteen 

 jointed, first long and ovate, second short, subquadrate, third and fourth nearly 

 equal, fifth and the following short. Mesothorax transversely and unevenly 

 rugulose, and with short, scattered and closely appressed hairs. Parapsides very 

 slender and subobsolete anteriorly. The usual parallel, intermediate lines faint 

 and ending half way to the scutellum. Lines at the base of the wings present 

 but indistinct. Scutellum long and narrow, ending in a blunt, rounded point. 

 It is rugose and hairy. Fovse small and rather widely separated. Abdomen 

 black and polished. The second segment is fully three-fifths of the entire length. 



TRANS. AM. KNT. SOC. XXVI. (40) JULY, 1900. 



