Siphunculata and Hemiptera 275 



HYMENOPTERA 



Adult insect with four, usually transparent, wings, wanting in 

 some species. Mouth parts adapted for biting and sucking; palpi 

 small; tarsi four or five-segmented. Metamorphosis complete. 

 Parasitic four-winged flies, ants, bees, and wasps. 



SIPHUNCULATA AND HEMIPTERA 



a. Legs with claws fitted for clinging to hairs; wings wanting; spiracles of the 



abdomen on the dorsal surface. ( = ANOPLURA = PARASITICA) 



SIPHUNCULATA. 



b. Legs not modified into clinging hooks; tibia and tarsus very long and 

 slender; tibia without thumb-like process; antennae five- segmented 



ILEMATOMYZID.E Endr. 



H&matomyzus elephantis on the elephant. 



bb. Legs modified into clinging hooks; tibia and tarsus usually short and 

 stout; tibia with a thumb-like process; head not anteriorly pro- 

 longed, tube-like. 

 c. Body depressed; a pair of stigmata on the mesothorax, and abdominal 



segments three to eight; antennas three to five-segmented, 

 d. Eyes large, projecting, distinctly pigmented; pharynx short and 

 broad; fulturae (inner skeleton of head) very strong and broad, 

 with broad arms; proboscis short, scarcely attaining the thorax. 



PEDICULID^; 



e. Antennas three-segmented. A few species occurring upon old 



world monkeys Pedicinis Gerv. 



ee. Antennas five -segmented. 



f. All legs stout; thumb-like process of the tibia very long and 

 slender, beset with strong spines, fore legs stouter than the 

 others; abdomen elongate, segments without lateral pro- 

 cesses; the divided telson with a conical process posteriorly 



upon the ventral side Pediculus L. 



g. Upon man, 



h. Each abdominal segment dorsally with from one to three 

 more or less regular transverse rows of small setae; 

 antenna about as long as the width of the head. Head 



louse (fig. 65) P. humanus. 



hh. "No transverse rows of abdominal setae; antenna longer 

 than the width of the head; species larger." Piaget. 



Body louse of man P. corporis. 



gg. Upon apes and other mammals P. pusitatus (?). 



ff. Fore legs delicate, with very long and slender claws; other legs 

 very stout with short and stout claws; thumb-like process of 

 the tibia short and stout; abdomen very short and broad; 

 segment one to five closely crowded, thus the stigmata of seg- 

 ments three to five apparently lying in one segment; segments 

 five to eight with lateral processes; telson without lateral 



conical appendages (fig. 69). Crab louse of man 



Phthirus pubis. 



