EEVISIOlSr OF KEARCTIC TERMITES. 3 



The protliorax is well separated from the rest of the thorax. The 

 pronotum is of two general shapes, either more or less fiat and broad- 

 est in front, or with depressed sides and broadest ill the middle. 

 The thorax shows a median suture above. The legs vary in size, 

 the tibiae usually longer than the femora, with a few spines, at least 

 at apex, and the tarsus of three or four short basal joints and a 

 much longer apical joint, bearing the simple claws. The tarsi vary 

 but little, but the tibiae and femora may be greatly enlarged or 

 very slender.^ 



The abdomen consists of 10 segments, the fu-st is indistinct or 

 absent below; the apical ventral plate is divided into two, each 

 bearing a two to six jointed cercus (cerci) near its outer edge. In 

 the male, and in some cases in the female also, there is a pair of 

 stylets near the middle of the hind edge of the ninth ventral segment- 

 In the female of some forms the ninth segment is also divided into 

 two parts. In both sexes one or more of the basal ventral plates may 

 show a median division. No sexual organs are visible. (PI. 1, fig. 2.) 



The wings are much longer than the body; several times as long 

 as broad, usually with but fevv- veins, but in some forms there is an 

 irregular network of cross veinlets. The costal vein is very short 

 or absent in our species; the subcosta also short, the radius reaching 

 near the tip of wing. The radial sector arises near base of wing and 

 runs close to and j^arallel to the radius. In the more primitive 

 forms it bears several superior branches. The median often has 

 one or more branches, and the cubitus has several oblique branches 

 to the hind margin. In one section the median and cubitus and 

 their branches are colorless. 



The wings have near the base a m.ore or less distinct transverse 

 impression. After flight the insect breaks off the wings at this 

 point; the part remaining is the wing-scale, and shows the beginning 

 of the venation. The body and sometimes the wings bear hairs; the 

 wing scales are hairy as the body. 



In the soldier the head is enlarged and usually elongate; the man- 

 dibles usually elongate, simple, toothed, or twisted. The antennae 

 usually have fewer joints than in the adult. In the wood-inhabiting 

 species the legs are usually short; in the species that wander about, 

 the legs are long and slender, and the thorax small. Most of the 

 soldiers have no eyes. 



The vvorker has a shorter and proportionally thicker head than 

 the adult, usually with short mandibles and a very large labrum. 

 The abdomen may be depressed, cyUndrical, or narrowed at base. 

 They show no trace of wings and usually are blind. 



It is not always possible to correlate the workers or soldiers with 

 the adults of a species. The workers can be placed in the genus^ 



1 See Snyder, 1919. 



