CAMERON. SOME ODYNERINAE OF THE SOUTHWESTERN UNITED STATES 125 



lower part of prothorax, mesothorax, middle of metanotum, and a more or 

 less large spot on the center of the basal abdominal segments ; the clypeus, a 

 large semi-circular spot on the front, the eye incision, a spot under the tegulae, 

 a spot on the sides of the sciitellum, and the postscutellum, are yellow more or 

 less tinged with rufous. The red mark on the base of the second abdominal 

 segment is of irregular form and may be incised laterally at the middle and at 

 the apex ; there may be a square or triangular black mark in its middle ; the 

 basal half may be black with an enclosed transverse oval spot on the sides ; 

 the yellow apical band on the first segment may be dilated backwards at the 

 sides. An example from Ormsby county, Nevada, has the upper part of the 

 head, the thorax, except the apex of pronotum, a mark below the tegulae, 

 one on the sides of the scutellum, the postscutellum, and the first and second 

 segments of the abdomen (except at the sides), black. This variety may be 

 known under the name oslari. 



This is a very variable species and very confusing, owing to some of the 

 varieties simulating other but distinct species. 0. orasns Cam., for example, 

 agrees with the last form that I have described, but may at once be known by 

 the incised apex of its clypeus. 0. bradlcyi Cam., could be matched in color 

 by one of the aberrations, but may be known by the apex of the clypeus not 

 being transverse, and by the very different form of the antennae. 0. belti 

 Cam., fro'm Nicaragua is very similar in coloration, but has the clypeus longer 

 compared with the width, and otherwise differs in the middle of the metapleurae 

 at the sides projecting into a distinct tooth. 



Some of the forms are not unlike Rhygchium dorsalc F., in coloration. 

 Two characteristic features of the species are: the broad clypeus truncated at 

 the apex in both sexes, and the form of the second abdominal segment, which 

 is broader than long, its apex depressed, the depression widest in the middle 

 and strongly punctured. 



Odyneriis sapelloensis n. sp. 



Black, the clypeus except for a small black spot (broad and round above, 

 narrowed beneath shortly below the middle), a mark over the antennae, a line 

 on the base of the mandibles, a line on the base of the thorax, narrowed in the 

 middle, an irregular oval mark (straight behind, rounded in front and nar- 

 rowed), tegulae, base of postscutellum, two small irregular spots on the sides 

 of the postscutellum, two small irregular spots on the sides of the metanotum. 

 the apex of first abdominal segment (the sides of the apical half more broadly, 

 the yellow projecting towards the center so that the black central part is nar- 

 rower than the apical), the sides of the second segment from near the base 

 (the yellow projecting into the central part at the base, the apex more nar- 

 rowly), the greater part of the following segments, the apex of the second 

 ventral and the greater part of the following except the last, sulphur yellow ; 

 the apex of the femora above, their lower part more broadly (especially the 

 anterior), and the tibiae and tarsi, of a more rufous yellow, the rufous tint 

 most distinct on the tarsi. Wings almost hyaline, clouded slightly with fulvous 



