1864.] 259 



This may not belong to Mesoleptus on account of its long ovipositor 

 and robust basal segment of the abdomen, otherwise it has the charac- 

 ters of that genus. 



4. Mesoleptus tibiator, n. sp. 



Black; most of mandibles, palpi, tegulse and trochanters, yellowish-white: 

 legs pale yellowish-red, the 2)osterior tibiae and tarsi black, the former with a 

 broad whitish band; wings hyaline, areolet minute, subtriangular, jjetiolated. 

 Male. — Black, opaque, thinly clothed with whitish pubescence, 

 more obvious on the face ; most of the mandibles, and the palpi, yellow- 

 ish-white ; antennae as long or nearly as long as the body, black ; teguhu 

 yellowi.sh-white ; metatliorax with the elevated lines well defined, the 

 central area moderate, subrotundate. Wings hyaline, iridescent; ner- 

 vures and stigma fuscous; areolet minute, subtriangular, slightly oblique 

 and petiolated. Legs pale yellowish-red, the trochanters pale yellow- 

 ish-white, the posterior coxae entirely black or dull rufous more or less 

 tinged with blackish, their tibiae black, with a broad whitish band on 

 the middle, their tarsi also black with their extreme base whitish. Ab- 

 domen black, slender at base, rather broad and compressed at tip ; first 

 segment gradually dilated at the apex, sometimes the apical margin 

 of the 2nd segment is obscurely pale ; ventral segments stained with 

 yellowish. Length 2i — 3 lines ; expanse of wings 4 — 4i lines. 



Hah. — New Jersey (Cresson) ; Illinois (Dr. Lewis). 



Much smaller than M. annulipes to which it is closely allied. 



5. Mesoleptus dubitatus, n. sp. 



Black; most of mandibles, palpi and tegulse, yellowish-white; legs in most 

 part and the apical margins of abdominal segments, dull rufous; wings hya- 

 line, areolet subtriangular, petiolated. 



Female. — Dull black, clothed with a thin pale glittering pubescence, 

 which is more obvious on the face and pleura; most of mandibles and 

 the palpi, yellowish-white ; antenna two-thirds the length of the body, 

 entirely black ; tegulte pale yellowish ; metathorax with the elevated 

 lines well defined, the central area rather large and subquadrate. Wings 

 hyaline, iridescent; nervures and stigma fuscous, pale at base; areolet 

 small, subtriangular, petiolated. Legs dull rufous, the trochanters yel- 

 lowish, the tibiae and tarsi more or less obfuscated; the posterior coxae, 

 their trochanters above, and the base of their femora within, black. 

 Abdomen rather short and stout, slender at base and becoming gradu- 



