Some African Rotifers. By J. Murray. 11 



with its two openings, resembles that of H. 'perforata Murray (15) 

 in its structure, in form that of H. perforata is quite different, 

 having a wide neck and short two-lipped posterior tube. The per- 

 foration is to the dorsal side, as in H. caudata, but, curiously enough, 

 the variety americana (18) has it on the ventral side, though the 

 tube is of course always dorsal in its relation to the animal inside. 



I can offer no suggestion as to the function of this posterior 

 tube possessed by these two species, it seems a plausible suggestion 

 that it serves for the ejection of the voided fcecal pellets which 

 cause so much labour to H. anyusticollis, since it has to get rid of 

 them through the neck tube, as there is no other opening. Mr. Bryce 

 suggested that it served that purpose in H. perforata, but H. caudata 

 throws doubt on this explanation, as in that species the tube is 

 occupied by the mysterious " tail." If it does serve for getting rid 

 of the pellets, even if that is not its chief function, we must suppose 

 the tail can be drawn in to allow of it. 



What is the purpose of the tail itself ? There is another species, 

 not yet described, which has a process in the same position, but it 

 is small and wart-like. That might be regarded as protective, in 

 common with the warts and spines on the trunks and feet of many 

 species (Pleuretra brycei, Callidina papillosa, etc.), as the animal is 

 not known to be a tube-dweller. The " tail " of H. caudata being 

 itself protected by a tube, can hardly be supposed to serve for 

 protection, 



Many tube-dwellers, such as H. lonyiceps and H. anyusticollis, 

 are often found without tubes, from which it would appear that 

 they may only secrete them for some special temporary use (as for 

 the depositing of the eggs), or that they are under the necessity of 

 leaving their tubes at times and constructing fresh ones. H. caudata 

 has never been seen alive without a tube, but dead examples are 

 often without cases. 



Habitat. — Uganda ; Old Calabar (N. D. F. Pearce) ; Katoomba, 

 N.S.W. (Brit. Antarctic Exped. 1907-9); Pretoria, South Africa 

 (J. Hewitt). 



Habrotrocha ampulla sp. n. Plate II. figs. 6a-6d. 



Specific Characters. — Small, with slender neck and elongate head; 

 rostrum short, antenna long and slender ; corona slightly wider than 

 cheeks, disks close together ; head greatly elongate between rostrum 

 and corona ; teeth two in each jaw ; inhabiting a trigonous flask - 

 shaped case with a narrow neck ; foot unknown ; reproduction 

 oviparous. 



General Description. — Length when feeding 210 /x, length of case 

 150 fi, diameter of widest part 100 p, of neck 15 /x, of corona 20 p, 

 length of antenna 20 p, egg 60 y, by 45 it. The head is very long 

 and narrow, scarcely wider than the neck. The disks are so strongly 

 inclined forward that they are in line with the long axis of the body. 



