1838. HOUSE—No. 72. 85 
land Farmer. Its perusal is earnestly recommended to all who take 
an interest in the history of the contagious diseases of plants. 
The insects of this family have the body cylindrical or globose ; 
the antenne with not more than ten distinct joints, terminated by a 
thickened, solid, or perfoliate mass, composed of two or three joints ; 
the joints of the tarsi or feet are not spongy beneath, and the anterior 
legs are dentated or toothed. 
Their larve are small, short, white grubs with horny heads, and 
six small feet attached to the three anterior segments. Their jaws 
. are very hard, and formed for cutting woody substances, which they 
reduce to fine powder. They remain one or two years in the larva 
state, and do not quit the trees which they inhabit until they have 
become perfect insects. The places of their exit are perfectly cy- 
lindrical holes. 
In Hylurgus, the body is cylindrical and is obtuse behind ; the an- 
tenne are short, composed of ten joints, the three last forming a round- 
ed mass. The last joint but one of the feet is divided into two lobes. 
Aylurgus terebrans, is a large insect, apparently capable of doing 
much mischief. It is very common during the months of April, May 
and June, on newly made board-fences, and on lumber wharves ; but 
I have not been able to ascertain upon what tree it resides ; though 
probably it inhabits some of the pines, hemlocks, or cedars employed 
as lumber. 
Hylurgus dentatus is found in October, on the trunks and under 
the bark of the red cedar. The bark of this tree is perforated by 
thousands of small holes, from which have escaped these little beetles. 
The female forms a cylindrical passage beneath the bark, where she 
deposites her eggs. The larve proceed from this path, in feeding, 
at right angles, forming on each side numerous parallel furrows, small- 
er than the central tube of the female. The larve live between the 
bark and the wood, and by their ravages loosen the former, and 
arrest the formation of new wood. 
In the insects, referred by Prof. Peck to the genus Scolytus, the 
body is short and cylindrical ; the thorax is arched so that the head is 
situated beneath its anterior part; the antenne are ten-jointed, the first 
joint is long, and thickened at the end, the second cup-shaped, the third 
to the seventh, inclusive, are minute, but gradually increase in size, 
