APPENDIX 



265 



enclosed in a sheath. There are a pair of four-jointed palps 

 or pedipalps. 



The opening of the genitalia is on the under aspect near the 

 head, and respiration is conducted by a pair of sieve-like 



FIG. 71. Mouth-parts of Ixodes. 



FIG. 72. Mouth-parts of Rhipicephalus. 



openings in the respiratory areas, situated close to the bases 

 of the fourth pair of legs. 



There are two great groups of the IXODID/E, Ixodina and 

 Argasina. 



