AKT. 16 NORTH AMERICAN ICHNEUMON-FLIES — CUSHMAN 11 



segment, broad apices of tergites 1-7 and 8 except in middle above ; 

 front leg stramineous with more or less distinct darker streaks on 

 upper surface of trochanter and femur and flexor surface of tibia, 

 and frequently on upper surface of coxa ; middle leg more testaceous 

 with dark markings faint or absent; hind leg testaceous, coxa with 

 upper surface yellowish and flanked on outer side toward base by a 

 dark streak, tibia near base more or less distinctly pale, at apex and 

 basitarsus at base black, tarsus otherwise white, calcaria apically 

 more or less, usually largely, white ; wings hyaline, veins dark, stigma 

 pale. 



Male. — Smaller and more slender, and less distinctly sculptured 

 and more polished than female ; face narrower and eyes less strongly 

 convergent; annulus centering on flagellar joints 13-14; front and 

 middle legs and hind coxae paler ; hind tibia white at base, black at 

 apex, and only obscurely red in middle ; tergites more or less red be- 

 tween basal black and apical white. 



The National collection specimens bear the following data: Type 

 and three other specimens, Texas, Belf rage ; Victoria, Tex., two speci- 

 mens, J. D. Mitchell, one reared March 23, 1909, " from mud-wasp," 

 and one reared January 10, 1916, under Hunter No. 3748-1 from 

 Agenia petiol-ata (Cresson) ; one, Dallas, Tex., April 24, 1907, F. C. 

 Bishopp; one, Kansas; one, Riley County, Kans., May 25, F. Marlatt; 

 one, Boulder, Colo., September, Cockerell ; one, Rockford, 111., reared 

 December 17, 1920, from Ceropales fraterna; one, Plummer Island, 

 Md., June 25, 1920, H. S. Barber; one Cabin John, Md., September 13, 

 1917, R. M. Fouts ; one, Georgetown,, D. C, H. H. Smith ; one, Car- 

 lisle Junction, Pa., August 28, 1909, W. S. Fisher; one, Durham, N. 

 H., Weed and Fiske ; and two without locality, reared, one on April 

 24, 1884,, from Agenia l)07iibycisa by T. Pergande, and one from old 

 nest of Scelifhroii caeTnentariuTJi inhabited by Psevdagenia meUipes. 



MESSATOPORUS RUFIVENTRIS. new species 



Structurally I can see na difference between this and dlscoidalis 

 (Cresson), and am inclined to think it merely a color variation. But 

 in the absence of a good variation series I deem' it wiser to describe 

 it as distinct. One of the specimens was compared by S. A. Rohwer 

 with the type of Mesostenus jocttsus Provancher and determined by 

 him as that species in spite of the difference in abdominal coloration. 



Female. — Length, 8 mm. 



Differs from dlscoidalis practically only in color of abdomen, which 

 is red with tergites more or less darker at base, the first yellow at base 

 and apex. 



Type-locality. — Cabin John, Md. 



Type.— Cat.' No. 40579, U.S.N.M. 



