170 W. MILNE ON THE 



A narrow wedge-shaped ridge risfes up from the middle, just on to 

 the sulcus bridge. This ridge is not straight up and down, but 

 bends in with a sharp curve, at the top, over the sulcus.bridge. 

 The sharp edge of the wedge is dorsal, and curves round over the 

 top, so that looking down dorsally, with the animal horizontal, 

 a sectional view of the top of the wedge is got, looking like a very 

 short stout ligule, apparently on the sulcus. It was thought at 

 first to be a ligular process. Seen from the side the wedge shows 

 broader (fig. 15). 



The egg is ovoid, both ends broad and equal. 



Habitat. — Ground moss, Uitenhage commonage (Mosel Road) 

 and Springfield. Fairly common. 



Otostephanos gen. no v. 



Type. — Otostephanos auriculatus (Murray) = Habrotrocha auricu- 



lata. 



Generic Characters. — Bdelloida having a ring of fair thickness 

 round the corona with short breaks dorsally and ventrally. 



Whether the ring is real or false, the appearance is so distinctive 

 that there is no difficulty whatever in identifying a species as 

 belonging to the group, after one is once known. It is easy 

 enough, with the 1 inch objective, to distinguish whether a 

 corona is ringed or not, even if it be one whose diameter is only 

 l/900th of an inch. 



Bryce (8) is of the opinion that the ring is a ghost one. Murray 

 (7) thought it real ; to me it seems real enough. I cannot 

 satisfy myself that the explanation that the ring is due to inter- 

 ference is sufficient, as for one thing there are many coronae 

 which have no rings, whose disposition of the primary and 

 secondary wreaths appears in nowise different from that of those 

 which have. Also, as Murray states, there is no trace of motion 

 in the ring, and the outline can be very clearly defined. 



There is difficulty also in accepting the ring as real. From 

 the lateral ear or loop appearance the ring seems to stand clear of 

 the corona, but the ring possibly has a connection through a 

 transparent membrane, the ring itself only being visible on 

 account of its thickness. The ring seems close to and connected 

 with the corona alongside the sulcus and also at the dorsal break. 



