COLORATION IN POLISTES. 85 



transversely wrinkled ; tegulse fulvous, margined with yellow. Abdomen strongly 

 sericeous, fuscous or black, varied with dull ferruginous, especially on the second 

 segment ; apical margin of each segment dilated laterally and slightly interrupted 

 medially, and an irregular spot on each side, largest on the second segment yellow ; 

 beneath ornamented much as above. Length 18 min. 



Male. Face and clypeus flat, and yellow as far up as and on a line with emargina- 

 tion with the eyes, cheeks beneath broadly yellow ; antennae long, yellowish beneath, 

 apex black. Thorax without any ferruginous colors ; sides of prothorax and pleura 

 anteriorly beneath pale yellow ; scutellum sometimes with only a lateral yellow dot 

 at base ; lateral stripes of metathorax sometimes wanting. Abdomen darker than 

 in the female, sides of the second segment with a large ferruginous blotch inclos- 

 ing a yellow spot ; lateral margin of the first segment yellow ; disc of the second, 

 third, and fourth ventral segments with a large triangular yellow mark, apical mar- 

 gins also yellow. Length 18 mm. 



Hab. Texas. 



P. nava joe Cress. 



Female. Head pale yellow, the venter, occiput, and tips of mandibles black ; a 

 yellow spot on each side confluent with the orbits ; clypeus rounded and ciliated 

 anteriorly, sparsely punctured and pubescent ; cheeks tinged with fulvous ; an- 

 tennae fulvo-ferruginous, the middle of flagellum black. Thorax velvety black ; 

 . posterior border of the prothorax broader in front, tegulae and scutellum ferru- 

 ginous ; the mesothorax has sometimes a faint stain on each side ; metathorax 

 pubescent, obliquely striated, with a deep central longitudinal channel. Abdo- 

 men longer than the head and thorax, sericeous, the first and second segments 

 above and beneath, except apical margins, broader on the second segment, and 

 the basal margin of the third segment above and beneath black ; the remainder 

 lemon yellow ; anterior half of apical margin of the second segment fulvous above, 

 shading gradually into the yellow, sometimes entirely fulvous ; third and remaining 

 segments have a faint central longitudinal fulvous streak and a lateral spot of 

 same color, that on third segment sometimes very distinct. Length 18-20 mm. 

 Hab. California, New Mexico, Arizona. 



P. flavus Cress. 



Female. Lemon } r ellow ; base of clypeus, vertex, and cheeks tinged more or less 

 with fulvous ; clypeus subdepressed, subquadrate, sparsely punctured, each puncture 

 giving out a short fulvous hair, apex angular, ciliated, the lateral angles with two 

 teeth, the inner one the longest ; tips of mandibles black ; space between the 

 antennae protuberant ; antennae entirely fulvous, darker above ; prothorax faintly 

 tinged with fulvous, its posterior margin yellow ; mesothorax fulvous, the incisures 

 and a longitudinal black line on the disc abbreviated posteriorly, black ; a faint 

 line on each side of the disc and the lateral margins yellow ; metathorax with a 

 deep central longitudinal channel ; tegulse with a median fulvous spot. Abdo- 

 men bright lemon yellow, not longer than head and thorax, subsericeous, a central 

 longitudinal streak posteriorly, a spot at the base of the first segment, a narrow 

 line across the middle, slight stains on each side of the first and second segments 

 at base, a transverse spot on each side near the apex of the second to fifth segments 

 connected by a slender arcuated line (both above and beneath) fulvous; basal 

 segment triangular, its apical breadth equal to its length. Legs faintly tinged 

 with fulvous at base and on the tarsi. Wings varied with fuliginous, darker along 

 the costa, a bright violaceous reflection ; base of both wings, a narrow longitudinal 



