1864.] 267 



19. Mesoleptus subtenuis, n. sp. 



Black ; most of mandibles, palpi, basal joint of antennte beneath, tegulpe, 

 legs, and middle of abdomen, yellow or reddish-yellow ; wings hyaline, areolet 

 minute, oblique, petiolated. 



Male. — Slender, black ; most of the mandibles and the palpi, yellow- 

 ish ; antennae as long or a little longer than the body, black, the basal 

 Joint beneath with a yellow spot ; tegulae yellowish ; the elevated lines 

 on the metathorax rather indistinct. Wings very faintly tinged with 

 fuscous, iridescent ; nervures and stigma fuscous, the former yellowish 

 at base; areolet minute, oblique, petiolated. Legs, including the coxas, 

 entirely reddish-yellow ; the posterior tibiae and tarsi sometimes slightly 

 obfuscated. Abdomen elongate, rather slender, rather broad and sub- 

 compressed at tip, black ; apex of the first, whole of the second and the 

 basal half of the third and fourth segments, reddish-yellow. Length 

 2f lines ; expanse of wings 4 lines. 

 Hah. — Illinois. Dr. Samuel Lewis. 



20. Mesoleptus nigripes, n. sp. 



Blaek : sput ou mandibles yellowish ; wings subhyaline, areolet small, trian- 

 gular, petiolated ; aj^ical half of the fourth and all the following segments dull 

 rufous. 



Female. — Black, rather short, clothed with a thin whitish pubescence; 

 each mandible with an obscure yellowish spot ; antennae rather more 

 than half the length of the body, entirely black ; metathorax with the 

 elevated lines well defined, the central area pentang-ular, moderate. Wings 

 slightly stained with fuliginous ; nervures and stigma black ; areolet 

 small, triangular, petiolated. Legs black, the anterior pair rufo-piceous 

 in front. Abdomen rather stout, the first segment and basal half of the 

 second, black, the remainder rufous ; apex broadly compressed ; beneath 

 stained with yellowish ; ovipositor rufous, exserted about one line. 

 Length 3j lines; expanse of wings 5-j lines. 



Hab. — Illinois. Dr. Samuel Lewis. 



21. Mesoleptus hostilis, n. sp. 



Black; mandibles mostly yellowish ; most of abdomen and legs obscure ru- 

 fous; wings hyaline, areolet minute, subtriangular, petiolated. 



3Iale. — Black, rather slender, clothed with a thin whitish pubescence; 

 each mandible with a large yellowish spot ; antennas as long as the body, 

 entirely black ; metathorax with the elevated lines indistinct, the cen- 

 tral area moderate, elongate. Wings hyaline, with a faint tinge of fuli- 



