BDELLOID ROTIFERA OF SOUTH AFRICA. 157 



animal is apparently anxious to feed, it may be seen hesitating 

 and evidently dubious about the advisability of unfolding the 

 corona. On these occasions the upper lip is pushed stealthily 

 forward, with its elbow bends compressed backwards into sharp 

 angles, and the ends of the collar apparently thrown forward 

 (fig. 6c). The corona is not yet unfurled, but the rostrum is 

 thrown back. 



When creeping it appears long and narrow, and makes a short 

 gentle glide. 



The inclosed wheels are a glaucous mass with a clear-cut 

 outline, small and round with a flattened front. The lateral 

 plicae are well marked ; and the cross dorsal marking, from 

 which the lumbar plicae spring, is unusually far forward. 



When feeding, the front trunk segment usually stands well out 

 from the neck (fig. 6). It feeds in the open. The jaws are 

 large, but the teeth are very small and difficult to see clearly, and 

 are possibly more than eight in number. The lumbar region is 

 not unlike that of Otostephanos torquatus-amoenus, and indeed 

 it is difficult to distinguish between the two species when 

 creeping. I usually look first for the long setae at right angles 

 to the rostrum which characterise 0. torquatus-amoenus. 



Habitat. — Ground and rock moss, Kamaehs, Euphorbia Kloof 

 and Springfield. It was fairly abundant. 



Another rather smaller form and probably a variety of the 

 above was seen. The corona was very slightly wider, and in the 

 upper lip the front part of the elbow-bend — if bend there were — 

 could never be certainly made out. Otherwise it had the same 

 appearance. It was deeply stippled. The number of teeth was 

 probably seven. 



Habrotrocha plana sp. no v. 



PI. 11, fig. 7. 



Specific Characters. — Short and broad with narrow extremities 

 of a bluish-grey colour. Lamella double with several long setae 

 under it. Antenna from one-third to one-half neck width. 

 Jaws large, teeth two, very small. Trunk very broad and slab- 

 like ; lumbar region of distinctive shape. Foot has possibly 

 four segments, a very narrow ankle and stout toes. Spurs short. 

 Contractile vesicle is large. Corona less than collar. Upper lip 

 triangular. Size, 1/lOOth to l/120th inch. 



