45 
Macq. The bacterial affection came to the notice of an assist¬ 
ant during my absence from the office, but was not systematic¬ 
ally investigated; and the sphaeriaceous fungi are of the genus 
Cordiceps (apparently C. melolontlise) , already well known to 
destroy white grubs. The bacterial difficulty was probably the 
cause of the almost complete disappearance of white grubs in 
the field of Mr. Plank, of Champaign, described under another 
head. Probably not one per cent, of the grubs present in this 
field June 1 finally reached the imago—a fact demonstrated by 
a careful examination of the earth later in the season. A con¬ 
siderable percentage of the grubs collected in this field at the 
date first mentioned were dead, with flaccid bodies; and others 
died, similarly affected, among those brought to the laboratory 
for breeding-cage experiments. 
DESCRIPTION. 
By a study of miscellaneous lots of white grubs collected for 
breeding purposes, my office assistant, Mr. C. A. Hart, was 
enabled to separate Cyclocephala from Lachnosterna, and to 
divide the larvae of the latter genus into three clearly distin¬ 
guishable groups, from which five species of imagos were bred; 
hirticula and rugosa from the first, in versa and fusca from the 
second, and gibbosa from the third. A further separation of 
the larvae of the above compound groups has not been found 
possible, and I do not know how to distinguish hirticula from 
rugosa, or in versa from fusca , in the larval state. Apart from 
differences of size, the main distinctions among these larvae, 
both generic and specific, are to be found at the tip of the ab¬ 
domen, the specific characters especially in the hairs and spines 
upon the ventral surface of the last abdominal segment. 
Genus Cyclocephala. —The tip of the abdomen and the sum¬ 
mits of the folds on the backs of segments' four to nine are 
crowned with short brown hairs, not thickly set. Segments one 
to nine are short, ten and eleven are equal and twice as long' 
as nine, twelve is more than three times as long, and segment 
thirteen is very short and followed by a large round anal plate 
which attains the tip of the abdomen. Anal slit transverse. 
The hairs on the ventral surface of the last segment are uni¬ 
form and irregularly scattered. The front and clypeus are a 
little roughened, the labrum somewhat more so; the mandibles 
slightly sulcate. 
C. immaculata. —The body of this species is cream-colored, 
and is covered with scattered soft brown hairs; the spiracles 
are orange; the head ferruginous, a short longitudinal brown 
line behind the usual frontal V, and a black dot at the base of 
each mandible. The first joint of the antennae is globose, the 
second is cylindrical, three times as long as the first, swollen 
near the distal end, the third is longest of all, the fourth 
shorter and prolonged into a short tooth anteriorly on the 
