17 
in the large pronotal spots. Metaiiotum with a distinct, strongly emar- 
ginate central longitudinal groove, the space either side finely granulate, 
with occasional irregular carinas. Abdomen longer than thorax; seg- 
ment 2 as long as 3, 4, and 5 together; 5 and 6, subequal. Antennae 
rather long and straight; pilose; joint 1 of funicle only slightly longer 
than joint 2; club not quite as long as three preceding joints together, 
strongly flattened from side. Face very slightly pilose; metanotal 
fimbria sparse. The whole insect is smaller, slenderer, and more deli- 
cate in appearance than any except grande, form minutum. 
Male. — Length, 1.9 mm; expanse, 3.4 mm. Petiole short, not as long 
as first abdominal segment and scarcely as long as hind coxa 1 , scape of 
antennae slightly widened; funicle joints very slightly rounded above 
and very slightly pedicellate; each more than twice as long as pedicel 
and each faintly constricted in middle; club divided into two pedicellate 
joints as with I. captivum. All legs black with light-yellow knees. 
Fig. 
■Isosoma tritici Fitch. 
Described from 11 females and 7 males reared by Mr. Albert Koebele, 
at Los Angeles, Oal., from Bromus ciliatus collected at Millard's Canyon, 
Los Angeles County, Cal. The adults issued in March, 1887, from grass 
collected September, 1886. 
Isosoma tritici Fitch (fig. 7). 
Eunjtoma tritici Fitch, Jour. N. Y. State Agricultural Society, 1859, vol. x, p. 115. 
Fsosoma h ordei Walsh, Amer. Entomologist and Botanist, Oct., 1870, vol. n, p. 332. 
Decatoma basilaris Provancher, Faun. Ent. Can., vol. n, p. 569. 
Isosoma nigrum Cook, Rural New Yorker, June, 1885, p. 314. 
Female. — Length, 1 mm.; expanse, 7.0 mm. Head, pronotum, and 
mesonotum strongly rugulose but not umbilicate-punctate except 
toward tip of scutellum, where an occasional umbilicate puncture 
occurs; metanotum also strongly rugulose with a faint trace anteriorly 
of a median longitudinal furrow; metanotal spiracles large and per- 
12284— No. 2 2 
