270 [September 



ceous at base ; stigma rather large, fuscous, pale at base and tip ; areolet 

 small, oblique and subpetinlated. Legs slender, yellowish ; the poste- 

 rior pair honey-yellow ; the anterior and middle coxjb yellowish-white ; 

 tips of tarsi blackish. Abdomen slightly petiolated, subclavate, dull 

 honey-yellow, apex obfuscated ; basal segment gradually dilated towards 

 the tip, the sides somewhat carinated. without tubercles. Length 4 

 lines ; expanse of wings 7 lines. 



Hah. — Pennsylvania. Mr. C. A. Blake. 



Same form as M. longicornia^ but differs by the head and thorax be- 

 ing black. 



Section 3. 



26. Mesoleptus longicornis. n. sp. 



Dull yellowish-red : head and pleura beneath, black ; face and tarsi yellow- 

 ish ; wings hyaline, areolet triangular, oblique, subj^etiolated ; abdomen sub- 

 petiolated. 



Malr. — Head transverse, black ; the face beneath the antennae, cly- 

 peus, mandibles and palpi, yellow ; antennae slender, longer than the 

 body, orange-yellow, slightly involute at tips which are blackish. Tho- 

 rax dull rufous, the dorsal lines tolerably well impressed ; pleura be- 

 neath and slightly on the sides, black ; tegulae yellowish, scutellum and 

 metathorax dull yellowish-rufous, the extreme sides of the latter with 

 a large black spot. Wings large, hyaline, somewhat iridescent ; ner- 

 vures fuscous, pale at base, stigma testaceous; areolet small, obliquely 

 triangular, subpetiolated. Legs pale honey-yellow, the posterior femora 

 obfuscated, their tibiae at tip blackish ; all the tarsi yellowish-white, the 

 claws blackish. Abdomen elongate, subclavate, subpetiolated, entirely 

 honey-yellow, slightly dusky at the apex ; basal segment sublinear. 

 slightly and gradually dilated towards the tip, without lateral tubercles ; 

 ventral segments stained with yellowish. Length 5 lines ; expanse of 

 wings 11 lines. 



/frr/;.— Delaware. Dr. Thos. B. Wilson. 



27. Mesoleptus concolor, u. sp. 



Dull houey-yellow ; wiug.s hyaline, areolet subtriangular ; abdomen elavate. 

 Female. — Entirely dull honey -yellow, slightly tinged with brownish, 

 shining, clothed with a thin pale, subsericeous pubescence ; antenna3 

 very slender, rather longer than the body ; tegulae pale yellowish ; meta- 

 thorax polished, the elevated lines distinct, the central area elongate, 

 with a large, quadrate area on each side. Wings ample, hyaline, glossy, 



