2S2 [Septemher 



Genus CTENISCUS. Holiday. 



1. Cteniscus mediatus. n. sp. 



Black : face, orbits, tegulse, a sutural line before the wings, coxfe and tro- 

 chanters yellowish ; rest of legs pale rufous ; wings hyaline, iridescent, areolet 

 oblique, petiolated : abdomen subsessile, with a yellowish spot at tip of each 

 segment. 



Male. — Black, polished; face, frontal orbits, cheeks beneath, cly- 

 peus, mandibles and palpi, pale yellow ; antenna; as long as the body, 

 black above, brown beneath, the basal joint beneath yellowish. Thorax : 

 tegulae, a broad sutural line before and a short line beneath the wings, 

 and an oblique line on each side of the pectus, pale yellow ; scutellum 

 rather convex, black, its tip yellowLsh ; metathorax with the elevated 

 lines tolerably well defined, the central area elongate. Wings hyaline, 

 beautifully iridescent ; nervures and stigma fuscous, pale at base ; areo- 

 let small, oblique and petiolated. Legs pale rufous, all the cox;\} and 

 trochanters pale yellow, the posterior tibiae and tarsi obfuscated. Ab- 

 domen subsessile, polished, somewhat flattened, black, all the segments 

 with an apical yellow spot on the disk above, the spots becoming more 

 transverse towards the apex ; the incisure between the 3rd and 4th 

 segments tinged with fulvous ; basal segment subopaque, slightly canal- 

 iculate ; base of 2nd segment somewhat depressed and uneven. Length 

 22 lines; expanse of wings 4 lines. 



Hah. — Illinois. Dr. Samuel Lewis. 



2. Cteniscus dorsalis, n. sp. 



Yellowish-brown; face, orbits, tegulse, a line before the wings, four anterior 

 coxfe and trochanters, and a spot on the disk of each abdominal segment, yel- 

 low; wings hyaline, iridescent, areolet oblique ; abdomen sessile, 



Male. — Yellowish-brown, polished ; the face beneath the antennae, 

 frontal orbits, lower half of the cheeks, clypeus, mandibles and palpi, 

 pale yellow ; antennae about as long as the body, rufo-piceous, the basal 

 joint beneath tinged with yellowish. Thorax : tegul^, a broad sutural 

 line before, and a short one beneath the fore-wings, pale yellow ; scu- 

 tellum somewhat produced, with a large pale spot; metathorax convex, 

 polished, the elevated lines subobsolete. Wings hyaline, iridescent ; 

 nervures and stigma fuscous, pale at base ; areolet oblique, the 2nd re- 

 current nervure rounded outwardly, and received by the areolet at its 

 tip. Legs color of the body, the four anterior ,,coxae and trochanters 

 pale yellowish. Abdomen sessile, robust, only slightly narrowed at base. 



