224 THE ENTOMOLOGIST. 



II 1st segment much narrower and scarcely keeled. 



4. Jiavimanus, 2;^ — 2^ lines. 

 If Front coxae and trochanters pale, hind ones black. 



62. nycthemerns, 3 — 3^ lines. 

 t-ff All the coxae and trochanters whitish to pale yellow. 



61. oviventris, 2f lines. 

 =:=* Supero-niedial area broader than long, almost semicircular. 



1. caliginosus, 2^ — 'i^ lines. 

 =rv* Supero-niedial area distinctly longer than broad. 



37. cinctorius, 2+ lines, 

 b. Metathoracic arese not complete and distinct. 



Metathorax with two cross lines: supero-medial area not closed at 

 the sides. 

 =:= Hind tarsi not white-ringed. - 41. cephalotes, 3^ — 3i lines. 

 ■'fi-:- Hind tarsi distinctly white-ringed. - - tarsatus, 4|- lines. 



Section 2. — Scutellum pale ; abdomen black. 



Female. - - 37. cinctorius, 3 — 3| lines. 



Section 3. — Scutellum pale ; abdomen red and black. 



A. Metathoracic arege incomplete (females). 



Antennae tricoloured; aculeus more than half the length of the 

 abdomen. 



a. Abdomen red, apex black. - 44. congruens, 3 — 4;^ lines. 



b. 1st to 3rd segments of abdomen red. 43. graminicola, '2^ lines. 



B. Metathoracic arese complete and distinct (males). 

 Supero-medial area never quadrate; middle of abdomen red, face 



white-marked. 

 a. Front coxae dark. 



=:= Metathorax without spines. - - 16. cretatus, 2f lines. 



=:==:= Metathorax with very prominent spines. 22. pwnilio, 2-|- — 3 lines. 



h. Front coxae and trochanters pale. - 21. larvatus, 3|^ lines. 



C. Metathoracic areae incomplete or indistinct (males). 

 Supero-medial area, if present, quadrate ; face and mouth yellowish 



or pale-marked, 

 a. Antennae white-ringed. - - - 44. congruens, 5 lines, 

 b Antennae not white-ringed. 



•>= Middle of abdomen red ; tibiae red, apex of hinder black. 



f Front coxaB and trochanters pale. 53. arridens, 2^ — 3 lines. 



ft Front coxae and trochanters dark. 51. jucundus, 2-| — 4 lines. 



•-;::;: Middle of abdomen brown-red ; base of hind tibiae white (absent in 



a var.). ..... 5(5. basizonus, 3J lines. 



Section 4. — Scutellum black; abdomen red or red and black. 



A. Antennae black (females) ; var. ol' fiimator red at the base. 

 a. Metathoracic areae complete and distinct. 



=:- Abdomen distinctly narrower than the thorax, lanceolate. 



I4. nitidus, '2^ — 3 lines. 

 ** Abdomen as broad as the thorax, oval. 



f 2nd and 3rd segments of abdomen more or less red. 



