154 HICKORY. TRUNK WALNUT ANT DESCRIBED. 



resemblance to that of Unopodo vegetans (PI. 34, fig. 6), a species 

 which is quite common upon several of our American beetles. 



The An"t-tick measures from 0.010 to 0.015. It is of a cherry red color, 

 younger individuals being translucent and pale reddish; it is shining, with 

 translucent legs clothed with short hairs. It is of a circular form, very slightly 

 longer than wide, flattened, and commonly presents a translucent margin. 

 The legs arc shortish, taper gradually, and the feet are not half the thickness 

 of the shanks. The anterior legs have not the slender feet of the three other 

 pairs, but are antennaj-like, and have at their tips several short coarsish hairs 

 and a single bristle slightly longer than these hairs. The palpi or feelers rarely 

 project bej^ond the anterior margin, and their tips are also clothed with short 

 hairs. 



This ant appears to be a distinct species from those which have 

 been heretofore described, and I therefore propose for it a name 

 in allusion to the situation in which it occurs. It may be distin- 

 guished by the segments of its abdomen being glabrous and 

 polished at their bases and minutely punctured on their posterior 

 half, with two transverse rows of fine erect bristles, one in the mid- 

 dle the other at the tip of each segment. The Silky ant (Formica 

 subsericea) described by Mr. Say in the Boston Journal of Natural 

 History (vol. i, p. 289), is closely related to this species, but is 

 destitute of*punctures on the abdominal segments. 



The mai.es of this species measure 0.30 to the tip of the abdomen which is 

 about 0.08 in diameter, 0.32 to the tip of the closed wings, and the wings spread 

 0.45. They are black and shining. The head is nearly globular, and there 

 are, as usual in this sex, three distinct ocelli or little eyes upon the crown, and 

 from the anterior one of these a fine impressed line runs forward to the face. 

 The face is rough and unequal, with impressed punctures, from each of which 

 arises a short hair. The tips of the jaws are tinged with brown; the upper 

 lip is blackish-brown or sometimes cinnamon-yellow; the feelers are long 

 slender and thread-like, and are clothed with fine short hairs; the antennae are 

 long and slender, of equal thickness, their tips with an ash grey reflection. 

 The thorax is slightly broader than the head, oval, smooth, and without 

 punctures or hairs. The abdomen is somewhat wider than the thorax, and 

 composed of seven segments, of which the basal one is contracted as usual, form- 

 ing a slender pedicel, with an erect hump or scale on the middle of its upper 

 side, which, viewed laterally, is of a wedge-shaped form, short and thick, and 

 bears a few short hairs; its summit is cut off transversely and is distinctly 

 notched in its middle. The remaining segments form a regular oval mass, rounded 

 at base pointed at tip. The basal third or half of each segment is glabrous 

 and shining, the remainder is minutely punctulated and clothed with 

 fine short hairs, scarcely perceptible, whilst on each segment are two trans- 

 verse rows of fine bristles which are sometimes interrupted along the mid- 

 dle of the back, one row on the posterior margin, the other near the 

 middle, these bristles arising from rows of equidistant punctures. At the tip 



