thp: moke important families of acari. 



109 



retracted, in the same way as in the Metastigmata. Tliose of the blood- 

 sucking Mesostigmata are lancet-shaped. The mandibles are covered 



Fig. 5. — Leiidus Irnncatus, Oudms. ; female ; doiv^al and ventral side ; S = stigma ; 

 P=:peritrema. — Original. — A useful species. 



dorsally by the epistome, the anterior edge o£ which is characteristic for 

 almost every species. This epistome is fused with the maxillae on both sides, 

 forming thus a camerostome around the mandibles. The palps are filiform. 



:x^^^^ 



Fig. 6. — Dermonyssus galUncB (de Geer) ; female; dorsal and ventral side; S = stigma ; 

 P = peritrema. — Copied from Megnin, Les paras, et les malad. paras., tab. 1 ; 1880. — 

 A noxious species. 



The legs are generally slender, and placed contiguously on each side ; the 

 second pair of legs is generally thicker in the males. The genital aperture 

 in both sexes lies far forward ; in the males before the sternal shield, in the 



