124 A. C. OUDEMANS. ACARI. 



Megisthanus moaifensis Oudms. 

 (PI. II, fi'g. 24—29; Pi. III, fig. 30—39). 



1905 May 1. Megisthanus moaifensis nov. sp. OuDEMANs in Entomologische Berichte, 

 n°. 23, p. 222. 



Patria New Guinea (Moaif). 

 Found June 1903, by Mr. Lorentz. 



Female (Fig. 24—39). Lengtli 2100,0.; greatest width 1255, a. Colour brown like that of 

 Parasitas crassipes (L.). Shape oval, anteriorly truncate, greatest width on a line with the 

 stigmata. Texture smooth on the hard parts, finely wrinkled on the weak parts ; on the dorsum 

 there is a pore behind each hair. 



Dorsal side (Fig. 24) protected by one oval shield which anteriorly is truncate; on the 

 sides and posteriorly surrounded by a narrow margin of weak skin. Hairs abundant, long, 

 slightly curve, finely pectinate on the convex side (Fig. 26) ; in gênerai radiating from the 

 centre of the dorsum, anteriorly smaller, posteriorly longer. Noticeable are a bare space on 

 the posterior end of the dorsal shield and five pairs of short, strong, curve bristles exactly 

 on the posterior edge of the abdomen. There are seven vertical hairs, of which one longer 

 is médian, but I think this is accidentally. 



Ventral side (Fig. 25). Trito sternum (Fig. 27) of the usual shape, rather short, posteriorly 

 twice wider than anteriorly, covered with a double row of almost square scales, distinctly 

 demarcate from the long feathered slips. Jugular shield (Fig. 25) single, médian, transverse, 

 narrow, with sharply pointed extremities, a little excavate anteriorly to receive the tritoster- 

 num, provided with two hairs. Sterno-metasterno-ventral shield long, occupying the whole space 

 between the legs II, III and IV and a considérable part of the belly, narrowest between 

 legs IV, gradually becoming wider backward, posteriorly truncate, with rounded angles. The 

 latéral edges of the ventral part when lengthened backward unité with the latéral edges of 

 the large anal shield. The sternal portion is evidently only the part before the génital aper- 

 ture ; its bears the usual three pairs of hairs. The metasternal portions evidently are small, 

 triangular, behind the génital aperture and between this aperture and the foveolae pédales 

 II; each bears its single hair. The remaining of the shield must be considered as the ventral 

 portion, which is enormously developed because of the génital shield having moved so far forward. 

 It shows an interior marking behind the génital aperture, consisting in two granulate or 

 porate lozenge-shaped pièces, followed by a smooth triangular part. It is provided with 10 

 pairs of marginal hairs and a single submedian pair in the posterior part. Génital shield wholly 

 protecting the génital aperture, almost round-rhomboidal, wider than long, single, not double; 

 it shows, however, two interior chitinous wavy lines, which simulate an opening or split be- 

 tween two valves; it is provided with two pairs of minute bristles. Anal shield more or less 

 trapézoïdal, wider than long, anteriorly straight, scarcely concave, sides convex, posteriorly 

 convex; ail the angles rounded, (ratio length to width = 100 : 170); provided with 6 pairs 

 of hairs as follows : one in the anterior angles, one in the middle of the latéral margins, two 

 flanking the anus and two on the posterior margin, of which the outer one longer than the 

 other ones. Anus small, oval, shut by two valves, before the centre of the shield. The pedal 

 shields (circular chitinous rings around the foveolae pédales), the peritrematic shields and the 



