STATE AGRICULTURAL SOCIETY. 469 



CHESTNUT. TRUXK. 



cliaracters whicli 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 thorax 

 also is densely and confluenti}'' 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 edgea 

 are crenate-dentate, 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. bisalcatas. The basal part of the thorax with two shallow grooves. The 

 {qw specimens which I have received from the south are 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 scarel}' 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. 



19G. American' white axt, Termes frontalis, Ilaldeman. (Xeuroptera. 



Termitidse.) 



Myriads of white ants mining in and wholly consuming the 

 Interior of fence posts and stakes whilst the outer surface remains 

 entire. 



Tills insect has received its scientific name in allusion, I sup- 

 pose, to the deep notch wliioh occurs in front upon the heads uf 

 the soldiers, but as many other species are notched in the same 

 manner, I think tlie common name which I give it will be its 

 most apin'()})riate designation, since it is common all over our 

 country, and is the only species of white ant wliicli we liave in 

 tlie United States. Tlie workers or larva^ whicli furm much the 

 most numerous portion of each colony of these insects, are 0.18 

 to 0.20 long, wliite and glossy, with j)ale brownish a])domens 

 irregularly clouded with white. Winged individuals, su])posed 

 to be tlie males, make llieir appearance in tlie montli of May. 



