BDELLOID ROTIFERA OP SOUTH AFRICA. 163 



short cones, with flat interspace. Stippling heavy over all 

 trunk and foot, first segment of foot heaviest of all. Corona 

 fully equal to collar ; sulcus very narrow. Upper lip large, 

 right to top of corona, with a small notch in front. Size, up to 

 l/75th inch. 



This is a stout and very symmetrical animal with thick, leathery 

 but smooth skin. It is of the musculosa-ty^e as regards the 

 quick response to the action of the muscles, so that in whatever 

 position it is the shape for that position is practically constant. 

 The neck is extremely stout and fleshy, and its outline is made up 

 of three graceful curves not broken by the joints. 



The corona is fairly large, but is rather difficult to measure. My 

 measurements are, corona to collar as 9 to 9 up to 10 to 9. 

 The average would be about 10 to 9 J. 



The rostrum covers a large part of its segment when tossed 

 back. There are six teeth on each side of the dental bulb, three 

 large and three small. The small teeth are difficult to count, but 

 in the instances where I could count them the number was three. 

 The trunk is fleshed right up into the ridges, and shows dense 

 round the borders, where a considerable depth of skin is seen 

 owing to the boundary bend. This dense leathery shell or 

 rind-like part contrasts with the interior, and has a dark-greenish 

 tinge, like that described in Otostephanos regalis. It often acts 

 in the same peculiar way as 0. regalis when, having stopped 

 creeping with the intention of feeding, as shown by the 

 working of the jaws, and as if too timid to decide, it starts a 

 panting sort of action with a queer little shake of the head 

 up and down, and may continue this for a long time, before it 

 unfolds the corona. When it feeds, the head is kept very 

 steady, and the foot is generally hidden under the rump. 



The form of the rump is constant. There are three folds of 

 the thick skin on each side bulging out between the joints, or 

 apparent joints. The middle one looks something like the 

 prominence shown in the figure of H. crenata (Murray) (2, 3). 

 All the rump — bulges included — is heavily stippled or granulate. 

 I have never seen any crenate appearance even on the first 

 segment of the foot, which is the most heavily granulate part. 

 Evidently the granules are under the skin. The foot has four 

 segments ; the first is stout and curves out very delicately till 

 past the middle, and then curves inwards much more quickly. 



