460 Annals of the South African Museum. 



The outlines of the body, as seen from above, is shown in fig. 40. 

 The mite is very broad, in front nearly rounded, but posteriorly with 

 sharp angles, like A. tricuspidator (Miiller) ? , except that the angles 

 are more obtuse. The posterior margin reaches further backwards 

 than the angles, and is flatfish, rounded, and furnished with the 

 usual marginal hairs. 



The under side differs from that of the described species, particu- 

 larly in having smaller pore-plates (fig. 41) ; these latter are short, 

 weakly and regularly tapering and rounded at the ends. 



From the side a pair of dorsal humps may be seen externally to 

 the anterior curve of the dorsal line, which here bends a little inwards 

 (fig. 40). The humps are not pointed. 



The maxillary lip is very small. 



The maxillary palps (fig. 42) are large and well developed. The 

 fourth segment has a little saddle-like emargination on the extensor 

 side and a long cleft claio (fifth segment). It differs from that of 

 A. capensis n. sp. in having the large prehensile spine thick, short, 

 and weakly curved (fig. 42). The spine on the flexor side of the 

 claw is, on the contrary, very long and straight. The hairs on the 

 antagonistic portion of the fourth segment are relatively small. 



This mite is one of the largest Arrenurus females, like A. tricuspi- 

 dator (Milller) and A. auritus Koenike, 1898 (23). 



Locality. — Mr. Purcell collected 1 2 in a brack-water pond at 

 Zeekoe Vlei, Cape Flats (March, 1900). 



16. Akrenueus convexus ? , n. sp. 

 Plate XXL, figs. 43-45. 



Length of body 1-35 mm. 



Width ,, 1 10 mm. 



Height ,, 0-90 mm. 



The colour is brown. 



I am not quite certain whether this female belongs to the subgenus 

 Truncaturus Sig Thor, 1901 (32), or to the subgenus, Petiolurus 

 K. Thon, 1900 (33). I incline to the latter view, but it would be 

 necessary to see the male in order to decide. 



The shape of A. convexus ? appears broadly ovoid when seen from 

 above (fig. 43) or from below (fig. 44). The body is thick and highly 

 convex, the back being without dorsal humps. The dorsal line is 

 large and wide, without bends, and is closed posteriorly. 



On the ventral side (fig. 44) strong transverse wrinkles are 

 observable on the third and fourth pairs of epimera. 



