HICKORY. LIMBS — HICKORY-GALL APHIS. 155 



protrude three short thread-like processes, of which the outer ones are slightly 

 longer. The feet are long slender and tinged more or less with brownish towards 

 their tips. The single spur at the tip of each of the shanks is of a pale yellow color. 

 The wing? are transparent and glassy but not clear, the surface being minutely gran- 

 ular as usual in this genus and strongly iridescent. Their veins are honey-yellow 

 and have a waxy appearance ; those which traverse the posterior portion of the wings 

 are hyaline and colorless, and become abortive at their tips in the margin- 



, The TEMALEs differ from the males in being of a much larger size, measuring 

 almost half an inch to the tips of the wings, which, when spread, are three-fourths of 

 an inch across. The head approaches to a square form, and is broader than the 

 thorax; the upper jaws are more robust, and of a dark reddish brown color; both the 

 head and thorax are minutely punctured and pubescent ; the abdomen is propor- 

 tionally larger and less narrowed towards each extremity, is but six jointed, and has 

 no projecting processes at its tip, the scale on the peduncle at its base is very slightly 

 and sometimes not at all notched, and the two transverse rows of short bristles on 

 each segment are much more distinct ; the feet and sometimes the shanks are of a 

 dark reddish brown color; and in the wings the vein which bounds the inner side of 

 the cubital cell arises outside of the middle of the transverse medial vein, instead of 

 in the middle, which is the point where it originates in the males. Some females are 

 met with which have gnawed off their wings and cast them away, this being a com- 

 . mon habit among ants of this sex. These wingless females may be distinguished 

 from the largest sized workers by being of a still larger size, and the cicatrices 

 of the cast off wings are very obvious on the sides of the thorax. 



The NEUTERS or workers are always destitute of wings, and are generally smaller 

 than the males, varying in length from o.20 to 0.33. In all other respects they 

 resemble the females, except that they have no ocelli and a very narrow thorax 

 plainly divided into three segments by impressed sutures. The scale of the abdo- 

 minal pedicel is almost circular, being a little higher than it is wide, and is regularly 

 rounded above,^ without being cut off as in the female, or notched as in the male ; it 

 is convex on both sides, but with a slight concavity in the middle of its posterior face. 

 The following vaeieties may be found among these ants: 

 „. Female. Scale of the abdominal pedicel not at all notched.' 

 6. Female. Middle transverse sutures of the abdomen strongly constricted. 



c. Female. Middle suture of the abdomen pale, forming a transverse band. 



d. Neuter. Basal suture of the abdomen pale yellowish brown. 



e. Neuter. Two basal sutures of the abdomen pale yellowish biown. 



/. Neuter. Antennse and legs dark reddish brown, instead of black. These are 

 probably young individuals, recently hatched. 



Upon the twigs and leaf-stalks, hollow green bullet-like galls of a leathery texture, theli 

 inner surface covered with minute white and yellow lice ; the gall afterwards turning 

 black, opening and becoming cup-shaped. 



The HicKOKT-G.iLL Aphis. Pemphigus Caryacaulis, 



A disease of the young limbs of the hicliory, which will remind 

 one of the well known black knots upon the cherry, is of such 



