BRUES: NEW PHYTOPHAGOUS HYMENOPTERA. 



269 



Tenthredo infossa, sp. nov. 



Length 10.5 ram. Probably a female. Body stout ; dark in color. Head 

 black, the thorax more or less light colored anteriorly ; the scutellum and metan- 

 otuin black. Abdomen very dark, narrowly banded with pale on the sutures. 

 Wings hyaline, the veins unusually dark. Antennae black, the apical three 

 joints narrowing ; basal joints rather broad, the ones at the beginning of the 

 flagellum three or four times as long as thick. Head small and broad, two and 

 one-half times as wide at the temples as thick antero-posteriorly. Abdomen nar- 

 rowly oval, twice as long as wide ; the extreme apex not preserved, so that the 

 sex cannot be positively determined. Marginal cell moderately long, its cross- 

 vein only slightly curved ; first discoidal cell unusually short, hardly more than 

 twice as long diagonally as the length of the basal vein, and more rhombic in 



Fig. 9. — Tenthredo infossa Brues. Wings. 



shape than usual. First submarginal cell quadrate, the first abscissa of the 

 cubitus but little longer than the first transverse cubitus. Submedian cell longer 

 than the median by a little more than the length of the transverse median nervure. 

 Second submarginal cell receiving the recurrent nervure distinctly before the 

 middle. Anal cell slightly constricted at the cross-vein, suddenly widened out 

 behind toward the base to nearly triple its width at the cross-vein. Petiole at apex 

 of anal cell in hind wing as long as the vein closing the second discoidal cell. 



Type. — No. 2047, Mus. Comp. Zool., Florissant, Col. (No. 11,988, S. H. 

 Scudder Coll.). , 



One specimen in a fine state of preservation. 



This species resembles Macrophya to some extent, more especially on account 

 of the petiolated anal cell of the hind wing, but the form of the anal cell in the 

 front wing is that of Tenthredo. The legs are not at all preserved. 



