62 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.63. 



indistinct central carina on its posterior face; length of abdomen 

 to that of head and thorax united as seven and one-half is to three ; 

 abdomen extraordinarily flattened, looking as thin as a sheet of 

 paper when viewed from the side, at the middle of second segment 

 three-fifths as wide as the thorax across the tegulae; second tergite 

 two and one-half times as long as wide, as wide at base as at apex, 

 widest just before middle; basal foveae very short, indistinct be- 

 cause covered with short white hair, with striae not extending be- 

 yond their margins; apex of the second tergite broadly rounded, 

 semicircular as are the apices of all the tergites (except the terminal 

 one), the sides curved; third tergite two-thhds as long as the second, 

 twice as long as wide at base, the sides nearly parallel, diverging 

 very slightly anteriorly; fourth tergite two-thirds as long as the 

 third, twice as long as wide, as wide as the third at apex, the sides 

 parallel; fifth two-thirds as long as the fourth, one and one third 

 times as long as wide, as wide as the fourth, the sides parallel; last 

 tergite as long as the fifth, pointed apically, the sides straight; wings 

 hyaline. Reddish brown; antennae, palpi, and legs golden yellow; 

 "the flagellum slightly infuscated toward tip." 



Type locality. — Washington, District of Columbia. 



Type.—Cs,i. No. 24604, U.S.N.M. 



Redescribed from the type specimen in the United States Natioal 

 Museum. The antennae and interior wings were lost before I saw the 

 type. 



A remarkable form. The extraordinarilj' flat abdomen and the 

 peculiar structure of the apices of the tergites serve to distinguish 

 the species. 



28. PLATYGASTER FILICORNIS (Ashmead). 



Polygnotus filicornis Ashmead, Bull. 45, U. S. Nat. Mus., 1893, p. 321. 



Female. — Length 1.5 mm. Body rather short and stout; head 

 seen from above about twice as wide as long, the cheeks rather 

 full; occiput excavated, margined; occiput, vertex, and cheeks behind, 

 shagreened; interocellar area and extreme upper part of frons on 

 sides more finely shagreened; frons laterally very faintly aciculate, 

 below on sides with a few faint transverse striae, otherwise polished, 

 unsculptured ; antennae long and slender, gradually incrassated 

 toward tips, the flagellum about as long as the abdomen, all of its 

 joints longer than wide; pedicel nearly three times as long as wide 

 at apex, slightly narrowed proximally; third joint twice as long as 

 wide, the sides parallel, about half as long as the second, a little over 

 half as long as the fourth; fourth two and one-half times as long as 

 wide, very slightly narrowed proximally, narrower than the second; 

 joints five and six about twice as long as wide, as wide as the pedi- 

 cel and as long as the fourth; joints seven to ten, inclusive, thicker. 



