26 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



on tegulae, short lateral lines above tegulae on scutum, lateral spots 

 on scutellum narrowed and approximated medially, fascia on metano- 

 tum, curved fascia on median segment above, narrow laterally and 

 broad on posterior surface, where it may be interrruped medially, 

 lateral angles of median segment, sides of same almost entirely, 

 large spots on metapleurae, large spot covering almost the entire 

 mesopleurae and continuous with the yellow on mesosternum inclos- 

 ing a black spot in front of middle coxae, fascia on first tergite broad 

 laterally, widely and deeply emarginate on anterior middle, the 

 emargination usually extended back from its lateral angles to meet 

 the posterior black border thus inclosing a median bilobed yellow 

 spot, the remaining fasciae of similar pattern, second about as broad 

 as first, others narrower, medial emargination shallower and not 

 extended backward to meet the posterior black border of the seg- 

 ment, sixth fascia sometimes broken into three spots, apex of ulti- 

 mate tergite, first sternite except lateral basal spots, second except 

 basal border, broad fasciae on third and fourth and narrower ones on 

 fifth and sixth on some specimens, on others large connected lateral 

 spots on third and fourth and disconnected lateral spots on fifth and 

 sixth, coxae, trochanters except spot above, femora except stripe 

 above, tibiae except sometimes a minute stripe on posterior pair 

 above, tarsi except more or less above, pale yellow or yellowish wliite. 



The yellow is brightest on the legs, sides of thorax, and the under 

 sides of the abdomen. The under surface of the flagellum gradually 

 changes from yellow to testaceous toward the apex, where the ulti- 

 mate segment is slightly flattened and curved. The anterior tarsi 

 are conspicuously flattened and bear a moderately well-developed 

 tarsal comb, and segments three and four bear well-developed pos- 

 terior apical processes that are invariably black and are character- 

 istic of this species. The middle and posterior tarsi are less evi- 

 dently flattened, but segments 3 and 4, and 5 basally, are black 

 above. A male from Arizona shows the black marks only on the 

 anterior tarsi. The middle femora are smooth and the middle meta- 

 tarsus is curved, but is without spines on curved surface. The 

 second sternite is without process of any kind and the eighth bears 

 a discal spine. 



Female. — Black: Labrum, clypeus, mandibles except apices, scape, 

 flagellum basally below, frons below, large spot inclosing anterior 

 ocellus frequently united with yellow on lower part of frons, broad 

 anterior orbits, posterior orbits broad below and frequently contin- 

 ued across the posterior border of vertex, posterior border of prono- 

 tum and sides of prothorax except spot in front of tubercles, spot on 

 tegulae, lateral lines and pair of large discal marks anteriorly on 

 scutum, fascia on scutellum narrowed, sometimes interrupted medi- 

 ally, fascia on metanotum, curved fascia on dorsum of median seg- 



