130 POMONA JOURNAL OF ENTOMOLOGY 



abdominal segment are yellow, as is also the apex ; the oblique mark is large 

 and broad, the mark on the sides of the second segment is large, broad, and 

 widest on the outer side ; there are two spots on its ventral surface, which are 

 large and oval ; the incision on the clypeus is triangular and is deei>er and more 

 distinct than in afiproxhiiatns. First abdominal segment cup-shaped, wider 

 than long, almost smooth except at the apex, which is weakly punctured. 



The female ( from mountains near Claremont, California ) has the yellow 

 markings larger, the apex of the second abdominal segment is more deeply 

 punctured, and is distinctly reflexed, the clypeus is slightly broader than long, 

 has the apex depressed and transverse, and has in its center a large transverse 

 oval black spot, the yellow oblique mark on the first abdominal segment is 

 almost enclosed on the outer hinder part, the narrowed black part of the apex 

 being almost continued to the outer edge ; as in the male there are two large 

 irregular oval yellow marks. 



Odynerus crassispinus n. sp. 



Black, the clypeus, mandibles except the teeth, a line about two and a half 

 times longer than wide and of equal width over the antennae, a broad line 

 dilated above on the lower edge of the eye incision, a short line near the top of 

 the outer orbits, an interrupted line of equal width on the base of the thorax, 

 a large conical mark (the wide end above) below the tegulae, tegulae except 

 a large brownish spot on the inner basal part, base of postscutellum, a small 

 oblique longish oval mark on the middle of the first basal obdominal segment, 

 a line on the apex of the first abdominal segment of almost equal width, broad 

 lines extending backwards on the sides to near the base, broad lines on 'the 

 apices of the second to sixth ventrals and two large oval marks on the second 

 ventral near the outer edges, bright orange yellow. Legs of a paler yellow, 

 the coxae, trochanters, and basal two-thirds of the femora behind, black. 

 Underside of the antennal scape bright yellow, of the flagellum fulvous 

 brown. Wings clear hyaline, the radial cellule clouded, the stigma dark 

 fuscous. Male — Length 7 mm. Claremont, California. (Baker.) 



Hind coxae armed at the base with a stout tooth, narrowed towards the 

 apex gradually, and longer than it is wide at the base. Clypeus longer than 

 wide, broad and transverse at the apex. Apex of postscutellum broadly 

 rounded, narrowed. Metanotum with bluntly rounded sides, rough, the middle 

 finely closely obliquely striated. First abdominal segment cup-shaped, smooth, 

 the second as long as it is wide at the apex, its base smooth finely, the apex 

 more strongly punctured and flat ; the other segments are finely but distinctly 

 punctured. Pro- and mesopleurae distinctly but not closely punctured, the 

 metapleurae closely roughly obliquely striated. Characteristic of this species 

 arc the transverse broad ajicx of the clypeus, and the stout spine on the hind 

 coxae. 



Odynerus sulciventri.s n. sp. 



Red ; flagellum narrowly at the base, a large mark square in front obli(|uely 

 narrowed behind covering the ocelli, the lower jiart of occi]nit. a mark dilated 

 at the base on basal half of mesonotum, a n;irrower JDUgcr one down the 



