16 
club is subellipsoidal. The two latter differences, then, are specific 
simply, and the first is apparently founded upon imperfect observa- 
tion on the part of Haldeman. 
The generic characters are plainly brought out in the figures. 
Especial attention is drawn to the fact that the marginal vein is about 
equal to the stigmal in length. The apical cilia of the forewings are 
short; the lower border of the mesoscutar parapsides is strongly 
curved, the male genitalia are, in most specimens, strongly exserted, 
and the penis is not perceptibly notched. The female genitalia are not 
produced beyond the tip of the abdomen. The male antennae are 
3-jointed, lacking all trace of the two ring joints seen in the female. 
The club is very long, twice as long as that of the female, subcylin- 
drical, rounded at tip, and furnished with many long sensory spots. 
The mandibles are 3-dentate. 
ANALYSIS OF I III". SPECIES OF F.KKTMOCEKUS. 
Eyes hairy, antenna! club of female oar shaped cortii 
E\ 68 naked, antenna] club of female ellipsoidal calif or ulcus 
Eretmocerus corni Haldeman (fig. 2). 
Eretmocerus corni Haldeman. American Journal of Science, vol. ix, pp. 110, 
111, May, 1850. 
Haldeman's original description included both generic and specific 
characters confused together. The species lias not been found since, 
and we can only quote his words : 
"Two mutilated specimens of another species of parasite were raised 
with the preceding and imperfectly examined. The color is pale fla- 
vor; the wings have a subcostal nerve not quite straight, ending in 
a short stigmal branch about the middle, 
the wings m all other respects as in Ami- 
tus; feet slender and apparently pentam- 
FIG. 2 -Antenna of Kret, u. corni y. C()veml with nume rOUS 
Haldeman— very greatly enlarged ( re- > •' 
drawn from Haldeman). short erect bristles, more distinct than in 
Chelonus; head, thorax, and abdomen closely united, thorax large, 
abdomen with sides parallel and the apex obtusely rounded; in one 
specimen ( & ?) the abdomen seems but half the width of the thorax, 
and in the other its sides form straight lines with it; antennas (see 
annexed figure) Particulate, shorter than the body, scapus narrowed 
toward its apex, second articulation obconic, third and fourth very 
short, fifth oar-shaped (whence the generic name), longer than all the 
preceding united, widened toward the apex, which is obtusely rounded. 
It may possibly be parasitic in the larva of the Amitus described above, 
as it is somewhat less in size. I propose to name the genus Eretmo- 
cerus, and the species E. corni? 
Eretmocerus californicus n. sp. (figs. 1 and 3). 
Female (fig. 1). — Length, 0.8 mm.; expanse, 1.5 mm.; greatest width 
of fore-wing, 0.23 mm. Antennal scape short, inserted just above 
