LEAF-CHAFERS. 
87 
coloi and in the form ot tlie thorax ; but as these characters are varia- 
ble in both species, it would, perhaps, be more correct to regard them 
only as varieties. 
llie genus Phyllophaga , Harris, ( Lachnosterna , Hope,) is very numer- 
ous in species, many ot which, however, bear a close resemblance to 
each other. It is emphatically, but not exclusively, a North American 
genus, GO of the 11G known species being found in this country. They 
may be divided into five groups, according to the clothing of the body. 
In the first and most numerous group, of which the common May-beetle, 
P. fusca, may be taken as the type, the* upper side is smooth and shin- 
ing. The second group contains but one species, the 1\ lanccolata, Say, 
found mostly west of the Mississippi river, and remarkable for having 
the body clothed with small lance-shaped cinereous scales. In the third 
group the body is more or less clothed above with soft erect hairs. Two 
species of this group are common in some localities, the P. hirticula, 
Knoch, and the L. Georgicanct, of Gyllenhal. In the former the hairs 
on the elytra are arranged mostly in three rows, whilst in the latter 
they are equally distributed. The fourth group contains a small num- 
ber ol large species, in which the whole upper surface is densely clothed 
with short prostrate hairs or down. The P. iliois, Knoch, is the type of 
this group. The fifth group is composed of comparatively small spe- 
cies, about half an inch in length, of a pale color, partly smooth above, 
but with the thorax and base of the elytra densely clothed with long 
hairs. The P. tristis, Fab., the same as the P. pilosicollis, Knoch, the 
type of this group, is not uncommon. One other species is found in 
Texas. There is also a number of small pale species, half an inch or 
less in length, with the body glabrous, which might constitute a sixth 
gioup. the P. longitarsis , Say, is the type of this group, remarkable, 
as its name implies, for the length of the tarsi. 
It must be remarked that all the species of this genus are densely 
hairy on the under side of the breast, as indicated by the generic term 
Lachnosterna, of Hope. 
The common Rose-bug, (M. snbspinosus, Fab.) is the type of the genus 
Macrodactylus, Latr., a word meaning long tarsus. The Rose-bug is be- 
tween three and a half and four-tenths of an inch in length, covered all 
over with minute ochre-yellow scale-like hairs, which are not distinctly 
' isible without the aid of a magnifier. The thorax is also somewhat 
densely clothed with short upright hairs. A specimen from Georgia, 
with the hairs more conspicuous, has been described by Dr. LeOonte 
under the name setulosus. Another species, the mgustatus, Pal. do 
Hoauv., found in the Southern States, is distinguished by its longer 
thorax, and the absence of the erect hairs. The genus is exclusively 
