126 NEW YORK STATE MUSEUM 
from which it may be easily separated by differences in the color of 
the legs and in the emargination of the ventral plate. 
METADIPLOSIS Felt 
1908 Felt, E.P. N. Y. State Mus. Bul. 124, p. 406 
1910 Rubsaamen, E. H. Zeitsch. Wissenschaft. Insektenbiol., 15:285 
1911 Felt, E.P. N.Y. Ent. Soc. Jour., 19:59 
1913 Kieffer, J. J. Gen. Insect., fasc. 152, p. 211 
The genus is easily distinguished from the ordinary type of Itonid 
by the unique genitalia, the basal clasp segment being short, stout, 
broadly rounded and with conspicuous triangular, chitinous pro- 
cesses at the internal angles, while the terminal clasp segment is 
short, greatly constricted near the middle, enormously swollen and 
recurved apically. Type and sole species, Metadiplosis 
spinosa Felt. 
Metadiplosis spinosa Felt 
1908 Felt, E. P. N.Y. State Mus. Bul. 124, p. 406 
The unique male characterized below was taken July 14, 1906 on 
quack grass, Agropyron repens, at Albany, N. Y. 
Male. Lengthi1mm. Antennae one-fourth longer than the body, 
thickly haired, dark brown, the basal segments reddish; fourteen 

Fig. 21 Metadiplosis spinosa: a, fifth antennal segment of male, setae not 
sketched in; b, palpus of male (enlarged, original) 
segments, the fifth (fig. 21a) with stems three and three and one-half 
times their diameters respectively. Palpi (fig. 21b); the first segment 
short, stout, subrectangular, the second twice the length of the 
first, stout, the third a little longer and more slender than the second 
