100 



THE CRAB-LOUSE. 



THE CRAB-LOUSE. 



{PJifJin'his hufUfnaltK: orj>>dj/'.s Leach). 



This parasitic insect belongs to a different genus of lice, 

 as can be seen by its heart-shaped form and broad thorax, 

 which is not separated from the abdomen (fig. 68). The 

 former is composed of two segments soldered together, the 

 latter of eight flat joints. The first pair of legs are feeler- 

 like and possess slender tarsi ; the claws of the two other 

 pairs are large and strong, with a moveable thorn, to enable 

 the insect to secure a strong hold upon the hairs. The head, 

 broad in front, carries five-jointed feelers, and behind them, 

 upon two projections, the two simple eyes. The end of the 

 abdomen in the male is rounded, that of the female is bi- 

 lobed. Owing to the peculiar shape, the strong legs spread- 

 ing out laterally, this louse resembles a minute crab, hence 

 the name "crab-louse." It is of a whitish color, with a 

 dusky ill-defined spot upon each shoulder; the legs are red- 



Fig. 68. — Crab-louse of man. 

 Original. 



Greatly enlarged. 



Fig. 69. —Crab-louse 

 man, egg. Greatly < 

 larged. Original. 



dish, with darker claws 

 length, the female 1.2mm. 

 0.9mm. long and 0.5mm. 



The male measures 1mm. in 

 The pear-shaped eggs (fig. 69), 

 wide, are glued at their pointed 

 ends to hairs; about ten eggs are deposited. 



This species lives among the hairs of the pubic regions of 

 man, and, also, though not very frequently, upon the breast, 

 arm-pits, even in the beard, eye-brows and on the head. As 

 these nast}' parasites cling frequenth' to linen and other 



