MONOGRAPH OF THE NORTH AMERICAN PHOCTOTRYPID.E. ifi? 



Tribe ii. — Bikini. 



This tribe i>s of small cxtt'iit, jii)piirciitly, and for the most part, com- 

 prises species of the smallest size, the majority of which rarely attain 

 one millimeter in lenjjfth. 



The habitus of the species more closely resembles the Teleiiomini, but 

 the solid autenual club of the female, the ditt'ereuce iu venation of the 

 winged forms, the marginal vein being punctiform, or short and stout, 

 the stigmal vein short, thickened at base and terminating in a small 

 rounded stigma, while the basal nervure is usually present, and the 

 third abdominal segment, not the second, being the largest, readily 

 distinguish them. These difterences ~*nd the position of the lateral 

 ocelli will also separate them at once from the other tribes. 



The tribe Jiwini, as at present defined, will contain five genera : Thoron 

 Hal., AcoJuH riirst., Acoloiden How., CemtobmiH Ashm., and Bam Hal., 

 the parasitism of three of which is known. 



Species in the genera AcoIuh, Acoloidcs, and Jiau-s have been reared 

 in America from spider eggs; and I should not be in the least sur[)rised 

 to learn, from future observations, that the whole group contine their 

 attacks to Arachnid eggs. 



The genera may be di8tingnishe<l by the aid of the following table: 



TABLE OF GENERA. 



FEMAI.KS. 



Apterous forms , 2 



Wiuged. 

 First ahdominal segment without a horn at hase. 

 Mesonotiua with 2 furrows; tirst abdoiuiual sej^nicut petioliforni; eyes bare; 



lateral ocelli distant from the margiu of the eye Tiiokon Hal. 



First abdominal segment with a horn at base. 



Mesonotum without furrows CKi!Al()B.f:us Ashm., gen. nov. 



2. Scutellum distinct. 



Mesonotum without furrows; lateral ocelli close to the eye. 



First abdominal segment with a horn at base CER.vTon.Krs. 



First abdominal segment without a horn at base. 



First abdominal segment as broad as the metathorax and onl.y visible as a 

 transverse line; face with an antenna! im})rcssion, the occiput con- 

 cave, the superior margin sharp Acoi.us FJirst. 



First abdominal segment subpetiolate, much narrower than the metathorax ; 

 face not or but slightly impressed, the superior margin of the ocei- 



pui; rounded Acoi.oides How. 



Scutellum wanting Bjius Hal. 



MALKS. 



Winged. 



Mesonotum with two furrows; lateral ocelli distant from the margin of the eye. 

 Antennie filiform, the Hagellar joints about three times as long as thick. 



'- .J' . . Thoron Haliday. 



