No. 2368. AMERICAN SUBTERRANEAN GALLS ON OAK— WELD. 217 



(plate 32, fig. 16) are from cJiapmani. The outer spongy layer dis- 

 integrates with age leaving a hard woody cell 7 by 5 mm., with a wall 

 one-half millimeter thick. 



Type locality. — Fort Sheridan, Illinois. Galls collected October 3, 

 1914, on macrocarpa and alba, about half containing living adults 

 and half full-grown larvae. Others were found there on October 30, 

 on bicolor, and from another collected October 29, 1916, the adult 

 emerged in breeding cage on April 28, 1917. These galls have been 

 taken also at Winnctka, New Lenox, and Glen Ellyn, Illinois, on the 

 above hosts. 



Smoother button-shaped galls with the same radiate scar when 

 detached were found on the roots of chapmani at Ocala, Florida, 

 April 17, 1914, some empty and others containing full-grown larvae, 

 and again October 30, 1919, when half contained pupae and half 

 adults. More were seen at Clearwater and at Daytona and Daytona 

 Beach, Florida. Some of these, when opened December 3, gave five 

 larvae and two pupae which transformed December 1 2. These smooth 

 galls were also taken on roots of stellata at Mineola, Texas, September 

 2, 1915. They were empty. More were taken in fall of 1917 at Pop- 

 lar Bluff, Missouri, Texarkana, Arkansas, and two at Palestine, Texas, 

 from one of which a living fly was cut November 20, 1917. Similar 

 smooth galls were found on roots of prinus at East Falls Church, 

 Virginia, September 1, 1919, and one then cut open contained a pupa, 

 and three living flies were cut out on December 9. 



The normal emergence seems to be in spring, in April, and to be 

 distributed over two years. 



19. CALLIRHYTIS MAXIMA, new species. 



Plate 33, fig. 18. 



Female. — Very dark reddish-brown to black, with head, thorax, 

 and legs white-pubescent. Head finely granulate, eyes bare, man- 

 dibles two-toothed, palpi 5- and 3-segmented, antennae 14-segmented, 

 the last one and a half times as long as the preceding and in some 

 specimens incompletely or rarely completely divided into two parts. 

 Mesoscutum finely punctate, parapsidal grooves narrow, deep, smooth, 

 and percurrent; smooth black parallel lines extend back about as far 

 as lines over the base of wings extend forward; a notch on hind 

 margin is the only trace of a median groove. Scutellum rugoso- 

 punctate, with arcuate furrow at base separated by a more or less 

 distinct low median ridge into two smooth pits which open behind 

 on to disk. Propodeum with two straight almost parallel ridges 

 inclosing a slightly rugose area broader than high. Wings large, 

 transparent, veins brown, areolet distinct, pubescent, ciliate on 

 margin. Legs stout, punctate, tarsal claws simple, divergent. 

 Abdomen not compressed, smooth and shining except for large punc- 



