A. A. GIRAULT. 259 



each subequal to 5 ; 4 shorter, 5 longer, 6 still shorter than 4, a third 

 shorter than 5, a fourth than 7 ; the latter again longer and 8 again 

 shorter, a fifth shorter than 7 and consequently somewhat longer than 

 than 6 ; club joint long and only slightly wider than the funicle, as 

 long as funicle joints 2-4 combined, longer than the three preceding 

 joints taken together, bearing four or five short, curved, longitudinal 

 grooves. Antennas clothed with moderately short, soft, grayish pubes- 

 cence on the funicle, somewhat shorter on the club and which is too 

 dense to be arranged in distinct rows transversely or to be whorled. 



From 4 specimens, §-inch objective, 1-inch optic, Bausch 

 and Lomb. 



Male. — Described beyond. 



Described from four female specimens mounted in balsam 

 and all captured by the sweeping net as follows : One female 

 captured by Mr. C. A. Hart and myself while sweeping along 

 the edge of a cypress swamp, Pulaski, Illinois, May 14, 1910 ; 

 a single specimen of the same sex captured by myself while 

 sweeping along the edges of a brooklet running between an 

 old orchard in sod and a cedar grove at Butler, Illinois, July 

 14, 1910 ; and two females captured in the same spot, July 

 21, 1910. 



This species is interesting not only because of its foreign 

 aspect and gracefulness but because it is very probably para- 

 sitic on the eggs of some aquatic insect as its habitat and 

 structure would lead one to infer. It is also of interest be- 

 cause it either mimics or else is mimiced by an eulophid 

 which I captured at the same time at Butler and mistook for 

 specimens of this insect, and of whose difference I did not 

 suspect until all of the specimens had been examined under 

 the microscope. The eulophid has the same habitus and 

 the same general coloration, the contrasting pale coloration of 

 the base of the abdomen especially aiding the likeness of the 

 two ; it is a tetrastichine allied with Syntornosphyriim Foerster. 



Habitat. — United States : Butler, Vienna and Pulaski, Illi- 

 nois ; Riley County, Kansas ; Arlington, Virginia. 



Type. — Type No. 13,679, United States National Museum, 

 Washington, D. C, one female in xylol-balsam (Butler, 111., 

 July 14). Cotypes. — Accession No. 44,212, Illinois State 

 Laboratory of Natural History, Urbana, Illinois, three fe- 

 males in xylol-balsam, 2 slides (the 3 remaining specimens). 



TRANS. AM. ENT. SOC, XXXVII. 



