134 THE CANADIAN ENTOMOLOGIST. 



region rufous, palpi honey-yellow. Abdomen short but very deep, the 

 depth half again the length. Radial cell large, long triangular, length two 

 and a half times the width, terminal abscissa of the radius gently curved, 

 appendix below bent. Fort Collins ; June. 



Alloxysta longiventris, n. sp. 



Female. — Shining black, antennse at base and legs honey-yellow ; 

 head with vertex piceous, all below pale rufous. Length, i mm. 



Antennae 13-jointed, dark rufous beyond joint 4; flagellum strongly 

 enlarged toward tip ; proportions of antennal joints as in robusta. Meta- 

 notum with two longitudinal carinas which converge slightly anteriorly. 

 Abdomen nearly as long as the thorax, slender, upper and lower lines 

 subparallel. Radial cell small, short triangular, length two and a third 

 times the width, terminal abscissa of the radius strongly curved, appendix 

 below straight. Fort Collins ; May. 



In the form of the abdomen this species differs widely from any other 

 Allotriid I have seen. The abdomen of A. robusta differs from the normal 

 form in exactly the opposite direction. 



Alloxysta magna, n. sp. 



Female. — Large, robust ; shining black ; antennae at base and legs 

 honey-yellow; head rufous, slightly darker above. Length, 1,6 mm. 



Antenna; 13-jointed, piceous beyond the fourth joint; flagellum 

 subfiliform, scarcely enlarging toward the tip; joints i, 3 and 4 subequal, 

 2 about three-fourths as long, apical joint conical at tip, longer than the 

 anteapical. Metanotum with two longitudinal carinas which converge 

 sHghtly anteriorly. Abdomen globular, as deep as long, and scarcely 

 pointed behind. Radial cell large, triangular, length two and a half times 

 the width, terminal abscissa of the radius strongly curved, appendix below 

 short and straight. Fort Collins ; June. 



The largest species I have seen, and with the abdomen more nearly 

 globose. 

 Alloxysta gracilis, n. sp. 



Female.— Shining black, antennte at base and legs honey-yellow ; 

 head pale rufous. Length, 1.25 mm. 



Antennye 13-jointed, piceous beyond joint 4; flagellum subfiliform; 

 joint 3 equals one in length, 2 three-fourths as long, 4 and 5 somewhat 

 shorter. Abdomen from the side subtriangular, strongly pointed behind. 

 Radial cell of medium size, two and a half times as long as wide, terminal 



