159 



back entirely ; but in the female it is merely a small an- 

 terior plate (see Fig. 33). The capitulum or "false-head" 

 bears the mouth and the mouth-parts which together 

 form a projecting rostrum or beak. 



The Soft Ticks (sub-family Argantinae), e.g., Argaa 

 and Ornithodoros, have no shields ; and the capitulum 

 and mouth-parts (of the adult) are ventral, not projecting 

 in front. 



There are four pairs of six- jointed legs, each of which 

 has two curved claws with a sole or pulvillus. The two 

 front legs have each a small pit with sensory hairs (Mailer's 



Capitulum and_ 

 Mouth-parts " 



FIG. 32. Orniihodorus moubata. Ventral aspect. After Castellan! 

 and Chalmers. Note the ventral position of the capitulum and 

 mouth-parts. With permission, from Castellani and Chalmers' 

 "Manual of Tropical Medicine." 



Organ) on the terminal joint. There is a pair of stigmata 

 near the bases of the hindmost pair of legs. Eyes may 

 be present or absent. The anus is situated ventrally near 

 the end of the body. The genital opening is ventral, be- 

 tween the anus and the capitulum, in both sexes. 



Describe the Mouth-parts of a Tick. 



The four- jointed sensory palps (pedipalpi) are used as 

 feelers. The median ventral hypostome (or labio -maxillary 

 dart) has numerous recurved teeth ; it is thrust into the 



