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Indiana University Studies 



solid, the larval cells rather completely surrounded by wood. On Quercus 

 Douglasii. 



RANGE. — California: Napa, Auburn, Redding. Probably confined 

 to the more northern range of Q. Douglasii. 



TYPES. — 28 females, 36 galls. Holotype female, paratype females, 

 and galls at The American Museum of Natural History; paratype fe- 

 males and galls at the U.S. National Museum, the Museum of Com- 

 parative Zoology, the Philadelphia Academy, Stanford University, and 

 with the author. Labelled Napa, California; March 18, 1920; Q. Doug- 

 lasii; Kinsey collector. 



The insects emerged after collecting at Napa on March 

 18, 1920; galls collected later further north, at Auburn, on 

 March 31, and at Redding on April 2, showed all of the adults 

 to have emerged previously. 



The solid, woody gall is quite like those of the two other 

 varieties on Douglasii, namely kelloggi further south and com- 

 positus along the Sierras north of the Merced River. It is 

 similar to but definitely distinguished from the varieties on 

 other oaks. The insect is best distinguished by the broad 

 lateral lines ; it is entirely different in color as well as in some 

 other characters from kelloggi which occurs on the same oak. 

 In color it resembles compositus, ptignus, and pugnoides, but 

 is distinct from all of these in having a more or less completely 

 traceable median groove; from garrya7ise, which is of a sim- 

 ilar color and possesses a very much fainter median groove, 

 it is distinguished by the more definite median groove and 

 parapsidal grooves anteriorly, the broader lateral lines, more 

 largely smooth foveas, and complete cubitus. Nevertheless 

 atricinctus and garryanx are largely similar, just as their 

 adjacent ranges would lead one to expect. The galls of these 

 two, however, are distinct, as are the hosts and ranges. 



Plagiotrichus chrysolepidicola variety compositus, new variety 



FEMALE. — Shows the following characters in addition to those 

 common to all varieties of the species: Color generally dark rufous and 

 brown to piceous black; first two segments of the antennss yellow rufous; 

 parapsidal grooves fine, narrow, continuous to the pronotum; median 

 groove absent; anterior parallel lines not wholly smooth; mesopleurse 

 dark rufous brown, largely smooth, scatteringly punctate, most so 

 medianly, sparsely hairy; foveoe rather small, wholly, not closely rugose; 

 abdonien rufous to brown and piceous, mostly dark, not very hairy, not 

 as long as high ; areolet of moderate size ; cubitus not continuous ; length 

 2.0 mm. 



