NORTH AMERICAN HYMENOPTERA. 135 



44. Tetrastiolius flavipes n. sp. 



9. — Length .07 inch. Black, very elongate and slender; head much larger 

 than thorax and greatly emarginate in front with vertex sharp, region around 

 ocelli yellow testaceous; eyes brown; antennae 6-jointed, brown, pubescent; 

 thorax slender, elongated and not thick through, the collar is pointed, so that 

 the head appears prominently separated ; the scutellum has the usual two grooves, 

 space between it and the mesoscutellum deeply depressed ; abdomen ovate much 

 broader than thorax and slightly flattened, hairy; legs long, slender, the poste- 

 rior pair much longer than anterior pair, femora and middle of tibiae black or 

 brown, tibite and tarsi and base of fore-femora testaceous ; wings hyaline, bor- 

 dered with short ciliae, veins testaceous, marginal vein slightly thickened, post- 

 marginal wanting, stigmal short. 



Described from three S specimens bred from Cynipidous oak gall 

 Holcaspis fidgera Ashm. 



OX\0:fIORPHA F5rster. 



45. Oxyoniorplia livida n. sp. 



5 . — Length .14 inch. Uniform dark blue, including legs, excepting the first 

 three tarsal joints, which are pale or white, and the upper surface of the thorax 

 which has a greenish metallic tinge ; the antennae are black and haii-y ; thorax 

 punctate; abdomen is very long and slenderly pointed; wings hyaline, with 

 pale yellowish veins, the marginal vein is long and thickened, the stigmal short, 

 while the postmarginal vein is long. 



Described from one 9 specimen swept from bushes in a low 

 swampy meadow. 



This genus was founded by Dr. Forster in 1856. " Hymenop- 

 terologische Studien II Chalcidias und Proctotrupii p. 145," and this 

 is the first species described in our fauna. 



A Review of the species describetl by Olivier in the 

 *• Eutomologie." 



BY GEORGE H. HORN, M. D. 



In the folloAving pages it is proposed to pass in review the species 

 described by Olivier, whether originally by himself or by quotation 

 from others, cited from our fauna. These species have been gone over 

 so frequently in past years that it seems to have been assumed that 

 nothing remained to be done. Really comparatively little new will 

 be found in the following pages, but it is deemed sufficient to warrant 

 the publication of the entire list. 



The " Entomologie" consists of six large quarto volumes of text 

 and two of plates, which bear date as follows : vol. i, 1789 ; vol. ii, 

 1790 ; vol. iii and iv, 1795 ; vol. v, 1807 ; vol. vi, 1808. In the first 

 four volumes the different genera are treated as if distinct pamphlets, 



