51 
3. Last ventral of male convex, penultimate with a subcircular rugose 
depression, limited in front by a small narrow arcuate elevation, 
feeble at middle, on each side more distinctly and sharply elevated, 
extending obliquely outwards; clypeus deeply and acutely emargi- 
nate, front glabrous; thoracic punctures moderately coarse, rather 
sparse. 14-17.5 mm. implicita, Horn. 
Last ventral of male with smooth cupuliform depression, penultimate 
with elongate concavity at middle along hind margin, in front of 
which is a short obtuse punctate arcuate elevation; front with 
erect hairs, clypeus broadly not deeply emarginate; thoracic punc¬ 
tures rather coarse and sparse, irregularly placed. 15-16 mm. 
balia , Say. 
r Last ventral of male broadly concave, penultimate with a feeble arcu¬ 
ate elevation; front with short erect hairs, clypeus deeply emarginate; 
thoracic punctures coarse and deep, sparsely and irregularly placed, 
often leaving large smooth spaces. 14.5-16 mm. villifrons , Lee. 
3 Last ventral of male concave, penultimate with an obtuse transverse 
ridge divided by a depression at middle; rufotestaceous: clypeus 
emarginate; thorax moderately coarsely punctate, not closely, but 
somewhat irregularly. 14-18 mm.. limula , Horn. 
1 Hind tibia of male with one spur fixed.30 
Hind tibia with both spurs free.31 
) Surface with erect hairs, those of elytra in rows, (sometimes indistinct 
from rubbing); base of thorax channeled each side; penultimate ven¬ 
tral of male with a broad and long transverse impression, limited at 
each end by a smooth oblique plica, space in front slightly elevated, 
last ventral broadly concave: clypeus emarginate; thorax variolately 
and irregularly punctate. 16.5-19 mm. hirticula , Knoch. 
Surface covered with short grayish pubescence; base of thorax not 
channeled; penultimate ventral of male with a broad transverse im¬ 
pression, a slightly oblique tuberosity at each end in front, last ven¬ 
tral feebly concave, broadly emarginate at apex: clypeus deeply 
emarginate; thorax very densely granulate-punctate, median line 
smoother, slightly elevated, [ciliata, Lee.) 19-23.5 mm.... .ilicis, Knoch. 
I Clypeus emarginate; surface with short yellowish recumbent hair; 
penultimate ventral of male vaguely concave at middle; thorax with 
margin coarsely serrate, coarsely and densely punctate. 17-20 mm. 
crenulata , Frohl. 
Clypeus entire.33 
l Subcylindrical, rufotestaceous; clypeus emarginate; thorax moderately 
punctate, with smooth median line; last ventral of male longitudinally 
subcarinate at middle, anterior margin elevated each side, penulti¬ 
mate with sharply limited cupuliform concavity, its margin rising 
into an acute rugose tuberosity on each side, hind tibial spurs slen¬ 
der. 15-16 mm.,.. Anepta, Fab. 
3 Surface with yellowish hair long on head, thorax, and about scutellum, 
short on remainder of elytra; thorax coarsely, closely punctured, last 
two ventrals of male broadly transversely impressed, anterior margin 
of last ventral elevated, penultimate with a short acute transverse 
carina near the front margin. 11.5-15 mm. tristis , Fab. 
SUMMARY AND CONCLUSIONS. 
0! the thirty-one species of white grubs of the genus Lacli- 
osterna which occur in Illinois, only six have as yet been bred; 
iz., gibbosa, inverse, fuse a, rugosa, implicita , and hirticula; 
>ut these six species are all abundant, some of them excessively 
o, and contain together by far the greater part of these in- 
ects occurring in the State. There are, in fact, only three 
>ther species, fraterna, ilicis , and tristis, which can be called 
