260 [September 



ally broader aud subcompressed towards the tip; black, somewhat shin- 

 ing, the apical margins of all the segments indistinctly dull rufous ; 

 ventral segments stained with yellowish ; ovipositor exserted about one 

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

 Ilab. — Illinois. Dr. Samuel Lewis. 



Resembles 31. tihiator in size and form, but the hind tibias are rufous 

 and the abdominal segments are obscurely tipped with rufous. 



6. Mesoleptus obliteratus. n. sja. 



Black : mouth, teguke, four anterior coxpe aud troclianters and the venter, 

 yellowish: legs pale fulvous; wings hyaline, iridescent, areolet wanting. 



Female. — Black, slightly pubescent ; most of mandibles and palpi 

 yellowish; antennae nearly as long as the body, black, basal joint be- 

 neath and the tegulae yellowish ; metathorax with the elevated lines ob- 

 solete. Wings hyaline, iridescent ; nervures and stigma fuscous, pale 

 at base ; areolet wanting. Legs pale fulvous, the four anterior coxae and 

 all the trochanters, yellowish ; the posterior coxae, tips of their tibiae 

 and most of their tarsi, black or blackish. Abdomen subfusiform, black, 

 rather slender at base, broad and subcompressed at tip ; first segment 

 rather broadly dilated at tip, slender at base ; ventral segments yellow- 

 ish ; ovipositor exserted about one line. Length 2^ lines ; expanse of 

 wings 4 lines. 



Hah. — Illinois. Dr. Samuel Lewis. 



7. Mesoleptus compressus. n. sp. 



Black; moutli and tegula3 yellowish; legs mostlj' yellowish-red; wings hya- 

 line, iridescent; areolet small, oblique, sub23etiolated; abdomen much com- 

 pressed. 



Male. — Black, slightly pubescent; most of the mandibles and the 

 palpi, yellowish ; antennte more than half the length of the body, en- 

 tirely black ; tegulae yellowish ; metathorax with the elevated lines 

 rather indistinct, the central area small and subquadrate. Wings hya- 

 line, beautifully iridescent; nervures and stigma pale ferruginous, the 

 former pale yellowish at base; areolet small, very oblique and subpetio- 

 lated. Legs pale yellowish-red, the anterior pair in front, the trochan- 

 ters, and the base of the posterior tarsi, pale yellowish ; posterior coxae 

 and trochanters above more or less blackish, their tarsi obfuscated. 

 Abdomen slender at base, very broad and much compressed at tip ; 

 entirely black, except a very obscure rufous stain on each side of the 



