1034 FAMILY XXXVII. — NEPID^E. 



out of the water, clinging together. When raked out of the water to- 

 gether with the mud and partially decayed vegetation, these insects 

 usually feign death, in which condition they readily escape detection, as 

 their flat bodies are effectively concealed by the black mud and decaying 

 plant tissue. When kept in an aquarium Nepa will reach for its prey 

 with its raptorial legs, but in no instance could it be induced to swim 

 or run after its prey. If a house-fly or dragon-fly nymph is carefully 

 and slowly brought toward the front legs, the claw-like tibiae and tarsi 

 slowly move away from the femora. If they are already extended and well 

 separated, as is often the case, the insect usually remains perfectly quiet 

 until the prey is actually placed between the outstretched legs, when sud- 

 denly it is seized and securely held. The piercing organs are then in- 

 serted into a soft part of the body and the insect begins to feed. 



"Nepa will not only use smaller animals than itself as food, but it 

 will also feed upon dragon-fly nymphs considerably larger and stronger 

 than itself, the struggles of the nymphs usually ceasing within a short 

 time after the piercing organs of a Nej)a have been pushed into their 

 bodies. That this is the effect of a fluid which Nepa injects into them was 

 only too well demonstrated on ourselves. While one of us was carelessly 

 holding several Nepas in a closed hand, one of the insects suddenly punc- 

 tured the palm, causing an intense pain and soon afterwards a consider- 

 able swelling. If Nepas are allowed to remain in a jar of water, con- 

 taining no vegetation or anything upon which they can crawl to the sur- 

 face, they will all sooner or later be drowned. We have kept them alive 

 three months in a flat dish with water in it, shallow enough for the in- 

 sects to reach the surface with their breathing tube, by feeding them 

 now and then with house-flies and dragon-fly nymphs." 



The eggs of Nepa are globular and bear at one end eleven 

 tubular filaments. They are inserted in the stems of water 

 plants so that the body of the egg is concealed while the 

 threads project above the surface of the plant in which the eggs 

 are inserted. 



II. Ranatra Fabricius. 1790. 227. 



Elongate, subcylindrical species having the head wider across 

 the eyes than long ; eyes very prominent, strongly protruding ; 

 pronotum four or more times longer than its greatest width, 

 subcylindrical, obtusely carinate above, its front margin slight- 

 ly widened and feebly concave, hind one deeply concave ; scu- 

 tellum narrowly triangular, convex, only about one-fourth the 

 length of claval commisure ; elytra closely embracing the sides 

 of abdomen, clavus and membrane both very long and narrow; 

 front legs slender, much shorter than and widely separated 

 from the others, their coxae nearly as long as pronotum, femora 

 thickened at base, curved somewhat upward and narrower to- 



