HEMIPTERA 



383 



laterally into angular or rounded projections, suggesting the name 

 of the typical genus. But the most striking character which dis- 

 tinguishes this group is the remarkable form of the front legs. These 

 are fitted for seizing prey. The coxa is somewhat elongated ; the femur 

 is greatly thickened, so that it is half or two thirds as broad as long; 

 the tibia is sickle-shaped, and fits closely upon the broadened and 

 curved end of the femur; both tibia and femur are armed with a 

 series of close-set teeth, so that the unlucky insect that is grasped 

 by this organ is firmly held between two saws; the apparently useless 

 tarsus is bent back into a groove in the tibia. Another striking 

 character is presented by the antennas, the terminal 

 segment being more or less enlarged into a knob. 

 Under the lateral margin of the pronotiim in Phymata 

 there is on each side a groove into which the antenna 

 fits. 



Only two genera are represented in our fauna, each Fig. 441. — 

 by six species. These are Phymata and Macrocephalus. Phymata er- 

 In Phymata the scutellum is of ordinary size; in Macro- 

 cephalus it is very large and extends to the tip of the abdomen. 

 Our most common species is Phymata erosa (Fig. 441). It is a 

 yellow insect, greenish when fresh, marked with 

 a broad black band across the expanded part of 

 the abdomen. It conceals itself in the flowers 

 of various plants, and captures the insects which 

 come to sip nectar. It is remarkable what large 

 insects it can overcome and destroy; cabbage 

 butterflies, honey-bees, and large wasps are over- 

 powered by it. 



Family ENICOCEPHALID^ 



The Unique-headed Bugs 



In this family the hemelytra are wholly mem- 

 branous and provided with longitudinal veins 

 and a few cross-veins (Fig. 442). The head is 

 constricted at its base and behind the eyes, and is 

 swollen between these two constrictions. This 

 is a form of head not found in any other Hemip- 

 ■ tera. Ocelli are present. The antennse are four- 

 jointed; the first, second, and third segments are 

 each followed by a small ring-joint. The beak is 

 four-jointed. The front tarsi are one-jointed, the middle and hind 

 tarsi two-jointed. The front legs are fitted for grasping prey, the 

 fore tarsi being capable of closing upon the end of the broad tibiae. 



This is a small family ; but few species are known from the entire 

 world, and only two have been described from America north of 

 Mexico. These are Enicocephalus formicina, found in California, 

 and Systelloderus bleeps, which has been found from New York to Utah. 



Fig. 442. — Systello - 

 derus biceps. (Af- 

 ter Johannsen.) 



