STATE AGRICULTURAL SOCIETY. 
469 
CHESTNUT. TRUNK. 
characters which are subjoined, in addition to those above stated, 
the Two-toothed Silvanus may be recognized. 
Its head and thorax are often of a darker shade than its wing covers, espe 
cially in the moist living specimen. Its wing covers have rows of close punc 
tures with a slightly elevated line between each alternate row. Its thorai 
also is densely and confluently punctured, and commonly shows a very fain* 
elevated longitudinal line in its centre. The angles at its base on each side art 
obtuse, and from these angles forward to the projecting tooth the lateral edges 
are crenatc-dentatc, having sixteen little elevated tubercles or minute teeth 
jutting out at equal distances along the margin. The point of the large ante¬ 
rior tooth forms a right angle. Upon each side of the head behind the eye is 
also a minute tooth of the same size with those along the sides of the thorax. 
The surface is slightly clothed with minute inclined bristles. 
In every group of these insects individuals will probably be found of the 
following varieties :— 
a. bisulcutus. The basal part of the thorax with two shallow grooves. The 
few specimens which I have received from the south arc all of this variety and 
have the grooves deeper and more distinct than they are in any of my New- 
York specimens. Erickson supposes this variety to be the Colydium sulcatum 
of Fabricius, but this can scarely be, since Fabricius characterizes that species 
as having the wing covers smooth and makes no allusion to any projecting 
teeth upon its thorax. 
b. carinatus. A distinct elevated line upon the middle of the thorax its 
whole length. 
c. planus. Thorax wholly destitute of a longitudinal line on its middle. 
190. American wniTE ant, Termes frontalis, Haldeman. (Ncuroptcra. 
Termitidse.) 
Myriads of white ants mining in and wholly consuming the 
interior of fence posts and stakes whilst the outer surface remains 
entire. 
This insect has received its scientific name in allusion, I sup¬ 
pose, to the deep notch which occurs in front upon the heads of 
the soldiers, but as many other species are notched in the same 
manner, I think the common name which I give it will be its 
most appropriate designation, since it is common all over our 
country, and is the only species of white ant which we have in 
the United States. The workers or larvje which form much the 
most numerous portion of each colony of these insects, are 0.18 
to 0.20 long, white and glossy, with pale brownish abdomens 
irregularly clouded with white. Winged individuals, supposed 
to be the males, make their appearance in the month of May. 
