152 Rev. T. A. Marshall's monograyh of 



membranaceous, often pale and pellucid. The hind coxae 

 are incrassated, elongate, approximate, and obliquely 

 inserted. 



The Arcolaires of Wesmael consisted of this subfamily 

 together with the Agathidides, both distinguished by the 

 minute 2d cubital areolet, resembling that of the true 

 Ichneumons. The Agathidides are known at once by 

 their narrow triangular radial areolet. Latreille's genus 

 JMicrogaster, co-extensive with this group, was first sub- 

 divided by Nees von Esenbeck into two sections, founded 

 upon the completeness or imperfection of the areolet. 

 The last species, however, of his 2d section, ^1/. riigosus, 

 belongs to the Agathidides, genus Orgihis. Haliday and 

 Wesmael worked upon the same lines as Nees. Ratze- 

 burg attempted some further divisions, also based upon 

 the characters of the areolet, but too minute and 

 uncertain to be generally acceptable. The arrangement 

 here adopted is that of Forster, confirmed and illustrated 

 by Eeinhard. Mirax and Acoelius are aberrant genera 

 discovered by Haliday. 



Table of Genera. 



(2) 1. Antennra 20-jointed; prse- andpobrachialareolets 



of equal length ii. Accelius. 



(1) 2, Antennte with less than 20 joints ; pobrachial 

 areolet longer than the praabrachial. 



(4) 3. Antenna} 14-jointed i. Mirax. 



(3) 4. Antennae 18-jointecl. 



(6) 5. Wings with 2 cubital areolets (the 2d being con- 



fused with the 3d) . . . . . . . . iii. Apanteles. 



(5) G. "Wings with 3 cubital areolets (the 2d being more 



or less complete). 

 (8) 7. Spurs of the hind tibise shorter than i the meta- 

 tarsus ; segments 2, 3 not or hardly impressed 

 with a transverse furrow . . . . . . iv. Microplitis. 



(7) 8. Spurs of the hind tibife longer than ^ the meta- 



tarsus ; segments 2, 3 impressed with a trans- 

 verse furrow . . . . . . . . . . V. Microgaster. 



i. Mirax, Hal. 

 Hal., Ent. Mag., i., 263 ; ii., 230 and 467. 



Maxillary palpi 4-, labial 3-joiuted. Antennae 14-jointed. Eyes 

 somewhat villose. Abdomen showing 7 segments above, 6 beneath, 

 smooth and shining. Radius of the fore wings hardly inchoate, 

 springing from the same point in the stigma as the 1st intercubital ; 

 two cubital areolets, the 2d imperfectly separated from the radial, 

 Terebra subexserted, 



