HEMIPTERA HETEROPTERA. 



693 



on aquatic animals and floating debris. As a rule the legs are long, but 

 Mesovelia, British, resembles the land bugs. Hydrometra, also British, 

 walks on the surface-film holding its body above the water. It is easily 

 drowned. Velia, British, prefers rapidly running water. The wingless 

 Halobates with some fifteen species is one of the very few genera of insects 

 found in the open ocean. Rhagovelia is also marine but found nearer the 

 shore in the Gulf of Mexico. The eggs are usually laid on water plants. 



Fam. 10. Henicocephalidae. The head is enlarged behind the eyes. 

 Rostrum very short. Elytra entirely membranous and well veined. 

 Front legs swollen. Only one genus Henicocephalus, widely distributed 

 with a dozen species. 



Fam. 11. Phymatidae. Anterior legs short and thick and often devoid 

 of tarsi. Strong predatory bugs. Phymata frequents daisies and other 

 flowers with which its colour harmonizes, and it preys upon visiting insects. 

 In some forms the tibia makes with the femur a very efficient form of 

 nipper or grasping claw. 



Fam. 12. Reduviidae. Short rostrum, in reposs lying free from head and 

 looped. Eyes large, ocelli 

 behind eyes. Elytra when 

 present in three portions. 

 Head very movable. Tarsi 

 3-segmented. A large and 

 important family of over 

 2,000 species, largely tropi- 

 cal. They are predaceous, 

 living on other insects, 

 and are very varied in 

 shape and colour. Redu- 

 vius, British, preys on 

 bed-bugs and cockroaches. 

 Nabis, British, mimics an 

 ant in its younger stages. 

 Conorhinus, Melanolestes 

 and Rasahus are known to 

 bite man in America, 

 sometimes with serious 

 effects. The eggs of the 

 Reduviidae are usually 

 very characteristic and 

 operculated. The family 

 is said to be free from 

 stink-glands. 



Fam. 13. Aepophilidae. 

 Small, with short head and 

 no ocelli. Very short 

 elytra, but no hind-wings, 

 present. This family con- 

 sists of but one species 

 found in the sea on the coast of France and England. 



Fam. 14. Ceratocombidae. Minute. Head prolonged in front, ocelli 

 present, eyes close to thorax. Rostrum free. Small and fragile bugs. 

 Dipsocoris is found on the stony margins of Scotch streams. 



Fam. 15. Cimicidae. Flat with very short elytra which often leave 



FlQ. 436. Nabis lativentris, young. 

 _, insect seen from above ; B profile. 



Cambridge. 

 From Sharp. 



