AMERICAN HYMKNOPTERA. 375 



notnm closely and distinctly punctured. The area on the median segment is 

 triangular, but longer than the width of the base; there are 4 oblique keels, the 

 inner reaching to shortly beyond the middle ; the apex of the area is shagreened ; 

 from the ai'ea 4 longish keels run to the sides, and there are also 4 or 5 keels on 

 the top of the pleurae on the basal part. On the meso-pleurae is a wide, not very 

 deep, oblique furrow; the part above this is raised. The four front coxse, the 

 femora below and the tibiic and tarsi are for the greater part testaceous as is also 

 the greater part of the hinder tarsi ; the basal third of the hinder tibise is white ; 

 the femoral tooth is small, but distinct. The pedicle of the 2nd cubital cellule is 

 longer than usual, being nearly as long as the 2ud transvere cubital nervure and 

 as long as the top of the 2nd cubital cellule ; the 1st recurrent nervure is received 

 distinctly in front of the 1st ; the 2ud at a greater distance in front of the 2nd 

 transverse cubital nervure. Abdomen smooth ; the marks are large, wider than 

 long and irregularly oval. The last joint of the antennse is less curved and the 

 pedicle of the 2nd cubital cellule longer than usual. 



Hab. — Santa Fe district New Mexico. 



This species may be separated from A. interditialis as follows : 



Base of scutellum with 2 yellow marks; the area on median segment with 4 

 oblique keels; the 2nd recurrent nervure received distinctly beyond 

 the 2nd transverse cubital peliolalus. 



Base of scutellum without yellow marks; the area on median segment with 2 

 oblique keels; the 2nd recurrent nervure joined to the 2nd transverse 

 cubital iiilerstitialis. 



Alyson inter!«titialis sp. nov. 



Black ; the lower half of the inner orbits, the clypeusand labrnm, the mandibles, 

 the short lines on the centre of the pronotum. a broader one close to the tegulse, 

 the four anterior femora and tibiae in front, the front tarsi and the base of the 

 hinder tibiae, pale yellow; the wings clear hyaline; the nervures and stigma 

 black, % . Length nearly 5 mm. 



Antenna" stout, covered with a dense microscopic pile, the scape yellow, the 

 flagellum i)ale fulvous beneath ; the last joint is thinner than the preceding and 

 is as long as it; the curve on the lower side extends from the base to the apex 

 The front and clypeus are covered with silvery pubescence; the front is less 

 shining than the vertex. Mandibles yellow, blackish at the apex. Thorax 

 shining; the upper part sparsely covered with pale pubescence; the area on the 

 median segment is longer than the width at the base; the two keels unite at the 

 apex and there are two oblique keels at the base on the inner side, which form 

 two somewhat triangular areae ; there are three or four short irregular keels 

 attached to the outerside of the lateral keels. Abdomen shining, the segments 

 thickly fringed with long pale hair; the marks on the 2nd segment are trans- 

 verse, somewhat pyriform in shape and bright lemon yellow in color. The four 

 front tarsi are for the greater part testaceous; the hinder pair are testaceous at 

 the base of the joints only. The apical slope of the median segment is finely 

 punctured as seen through a good lens, and is stoutly keeled down the centre; 

 the scutellar depression bears stout keels; the two recurrent nervures are inter- 

 stitial, there is no distinct oblique furrow on the mesopleurae ; the last segment is 



TRANS. AM. ENT. SOC, XXVIII. OCTOBER, 1902. 



