34 A. e. OUDEMANS, NOTES O N ACARI. 



Ventral side. Tritosternura (fig. 21) very short 

 and -wide, rounded, quite before the genital aperture. I could 

 not discern a demarcation between its main trunk and the 

 two flagellae which are of the usual type. Jugular shields 

 more or Jess L-shaped. An accessory s h i e 1 d, wich Ivvill 

 call the tritosternal shield (see also fig. 42), is crescent- 

 shaped and surrounds the genital aperture together with the 

 t ritosternum. 



Sternal, raetastern al, genital, ventral, anal, 

 inguinal and peritrematal shields fused, show- 

 ing only a fine line of demarcation between the genital and 

 ventral part. All the hairs of the ventral side are small 

 bristles, of the usual number and place, viz. three sternal 

 pairs, one raetasternal pair, one genital pair (compare with 

 the female, fig. 31), 17 ventral pairs and three circumanal 

 hairs. Cri bru m dorsal (fig. 18). 



Epistoma (fig. 22) ; a pair of sinuated fine lines demar- 

 cate distinctly the central streak from the coxae of the 

 maxillae. The median streak itself shows also some fine lines. 

 The anterior part is almost triangular and has a median 

 mucro flanked by a blunt one, of which the anterior edge is 

 almost perpendicular to the axis of the body. S t y 1 i short, 

 thin, sharply pointed. 



Mandibles (fig. 23) long, reaching, when wholly 

 retracted, nearly the posterior shield (fig. 1 8, dotted line), 

 dark brown, distinctly discernible by the transparency of the 

 dorsal shield. Chelae (fig. 24 internal and fig. 25 external 

 side) robust, crooked, more or less remembering us the beak 

 of a parrot. The tibial sense- ,'rgan lies far before the artic- 

 ulation of the lower jaw ; the tarsal sense-organ is long, 

 and lies rather far backward. Dorsally, nearly between the 

 two sense-organs, the chitinous cover of the upper jaw is 

 pierced by a short canal, which most probably is provided 

 with a third sense- organ ; T, however, could not detect any, 



