584 IV AR TRÀGARDH 



Thec a 1 c a r m a n d i b u 1 i is large , bent like a hook do wnwards and 

 backwards, almost in a semicircle, wider at tlie base than the 

 chela, and above ail more strongly chitinized, tapering gra- 

 dually throughout and ending in a fine point. 



As to the probable use of thèse différent parts, it seems 

 that the chela with its fine teeth acts as a saw with which the 

 mite pénétrâtes the skin of the host, whereas the calcar acts 

 as a hook for getting the gnathosoma securely attached to the 

 wound. 



The pa Ipi (fig. 104) are about twice as long as the mandibles 

 and bear only small hairs, except one stout, perpendicular 

 bristle on the 2nd joint subventrally and terminally. The 

 terminal joint is very small, appendiculiform, but provided 

 with numerous small tactile hairs. 



The mandibles of the f emale (fig. 105) are of quite a différent 

 shape, the basai half being wide and of equal width, whereas 

 the distal half tapers abruptly to less than one quarter of that 

 of the basai half, ending with a narrow chela, both jaws of 

 which cover up one another when closed. The jaws are provided 

 with 4 to 5 sharp teeth, pointing slightly backwards. 



Thehypostoma (fig. 105). I hâve been unable to discern the 

 structure of this as closely as might hâve been désirable. This 

 appHesespecially to themaxillary lobes, which on my prépa- 

 rations (1), seem to be entirely absent. The maxillary plates 

 are narrow, ensiform, with smooth edges without fringes, and 

 seem to be more strongly chitinized than is usually the case. 



Of the 4 hypostomatic hairs, which are placed almost in a 

 longitudinal row, the first three are inserted more closely to 

 one another than to the hindmost. The médian ones are small 

 and inconspicuous. The anterior one almost twice as long and 

 the posterior one half as long again as the anterior one. 



(1) Wliuru tlii'y ;in.' sccu iu siUe viuw. 



