BDELLOID ROTIFERA OF SOUTH AFRICA. 73 



inside. The trunk laterally is slightly convex, and the posterior 

 boundary always shows straight across with sharp corners. There 

 are deep furrows laterally, the ridges not showing fleshy, but 

 having a mica-like appearance ; the dorsal furrows are broad 

 and shallow. There is practically nothing to distinguish between 

 the anal and pre-anal segments, which make up a comparatively 

 light lumbar region. Both the intestine and the contractile 

 vesicle are rather small. The foot is fairly stout, and the first 

 segment is long and of a distinctive shape. It curves in and then 

 out, ending in a distinct flange, which overlaps, laterally, the 

 second segment. There are three of these flanges, and a good 

 view can be had of them, when looking down the dorsal boundary, 

 while the animal is feeding in a nearly perpendicular position. 

 The first is at the posterior end of the trunk, and stands out very 

 clearly ; the effect is heightened by a broad hollow just in front 

 of it. The second flange is at the back of the anal segment, and 

 also stands well clear of the surrounding parts. The third is the 

 one already described at the back of the first foot segment. They 

 are very distinctive, and add to the general effect of the many 

 graceful curves shown in the outline of this animal. 



The spurs are very short, slightly blunt, parallel, and having 

 an almost concave boundary between the tips. 



The corona is an elegant one of large dimensions proportion- 

 ately, the width being rather more than one-fourth of the fully 

 extended animal. There is a single seta on each wheel, rising 

 from a very small peg. Short pedicels support the wheels. The 

 corona is to the collar as 22 : 13. 



When the animal is feeding in a perpendicular position, and the 

 upper lip looked down upon, the front margin of the latter shows 

 two thick lobes, but when the animal is horizontal the anterior 

 border approaches more nearly a straight line. This would seem 

 to indicate that the lobes are much thicker, or deeper, laterally, 

 and thin out towards the middle. There are two green granules 

 in front of the rostrum, visible when the corona is unfolded. 



The two teeth are not of great size. In some cases there is a 

 third one, not much larger than the striae, but having a point 

 which can be defined. 



When the animal was anchored and feeding, the first two 

 trunk segments were always seen with the peculiar frill arrange- 

 ment shown in the drawing (PI. 5, fig. 11). 



