258 .MEMOIRS OF THE CARNEGIE MUSEUM 



Some are phytophagous or gall-makers; others live in the nests of Vjees and 

 wasps; others are parasitic upon gall-making Hymenoptera and Diptera; while 

 still others are genuine parasites on Coleoptera and other insects, and a few, repre- 

 senting my tribe RUeyini, destroj'^ the eggs of orthopterous insects. 



The family may be separated into five tribes as follows: 



.*^^ ... .>j^^ 



J'^^'^^^nP'*^' TABLE OF TRIBES. rj^^ 



orax seen from above short, not lousrer than the scutellum, usually d 



1. Metathorax seen from above short, not longer than the scutellum, usually distinctly shorter, and some- 



what abruptly declivous 4 



Metathorax seen from above long, always longer than the .scutellum and usually gradually sloping to 

 apex (in a single case quadrate and squarely truncate behind) 2 



2. Head not cornuted ; eyes oval or ovate, not round 3 



Head cornuted, much wider than the thorax ; eyes round Tribe I. Aximiui. 



3. Marginal vein slender, longer than the stigmal or rarely shorter, but never very stout or stigmated ; 



abdomen most frequently long in both sexes, in female conic-ovate or couically pointed ; antenuse 

 dissimilar in the sexes, in females usually subclavate, in males with the joints of the funicle con- 

 stricted or excised at apex with whorls of long haire Tribe H. Isosomini. 



4. Marginal vein short and stout, stigmated, either quadrate or semicircular 6 



Marginal vein usually slender, linear, rarely stout, but never stigmated, quadrate, or semicircular 5 



5. AntennsB 10- to 12-jointed, with only one ring-joint, and dissimilar in the sexes, in females filiform or 



subclavate, in males with the funicle joints excised or petiolate at apex, with whorls of long haiis or 



with sparse long hairs Tribe III. Eurytomini. 



AntennsB 13-jointed, with two or three ring-joints, and veiy .similar in the sexes, the funicle joints not 

 excised or pedicellate at apex, and without whorls of long hairs Tribe IV. Rileyiui. 



6. Antennse at the most 11-jointed, with 1 ring-joint, the funicle 4-jointed and very similar in both sexes, 



filiform or subclavate, without whorls of long hairs ; abdomen short, globose, or oval, never very 

 long or strongly compressed ; hind tibife with rigid bristles behind Tribe V. Decatomini. 



Tribe I. Aximlni. 

 Mr. Peter Cameron, in Biol. Centr. Amer. Hyra., Vol. 1, p. Ill, established for 

 Axima Walker and HontaUa Cameron, the subfamily A.rtiuhiiv. The two genera, 

 however, have nothing in common, are quite distinct in structural characters and 

 belong to different families. Mr. Cameron was evidently deceived in regard to 

 their relationship by a superficial resemblance in the structure of the heads of these 

 insects. Axima is clearly a eurytomid, as I first pointed out several years ago, while 

 Hoiitiiliu is a chalcidid allied to Dirhhius, and must be placed in my tribe Dirhhiini. 

 Axima is parasitic in the nests of the small carpenter bees, CeraUnUhc. 



TABLE OF GENERA. 



• 1. Females 2 



Males 3 



2. Marginal vein four or more times longer than the stigmal vein ; antennre ll-joiuted, the funicle 6- 

 jointed ; abdomen long, lanceolate, compressed Axima Walker (type A. spin! fro its Walk.). 



