162 Transactions of the South African Philosophical Society. 



excreta of the animal. In this species the excreta were observed to 

 be ejected in long, solid, cylindrical masses, falling clear of the 

 animal and tube. Growing on the tube were often to be observed 

 solitary stalked Protozoa with horseshoe-shaped nucleus. 



The exposed part of the tube was readily injured, and occasionally 

 individuals were seen protruding through an aperture in the injured 

 tube. 



The substance of the tube was semi-transparent, brownish, and of 

 a tough consistency where embedded ; in this region there were 

 no inclusions in the substance of the tube. There was evidence 

 that the tube is secreted by glandular epithelium of the body gene- 

 rally. Thus, if the animal is removed from the tube, there is an 

 active secretion of mucus, which soon causes the body to be covered 

 with any loose particles that may be in the neighbourhood. In one 

 case a fairly large active copepod was observed to become entangled 

 in the viscid secretion, and was soon rendered quite helpless. The 

 mucus is at first clear and transparent, but soon becomes whitish 

 and opaque. 



None of the tubes were straight, but had a more or less irregular 

 curve, sometimes even forming a loop. When tubes were removed 

 from the limestone by decalcifying, they were found to be densely 

 coated with firmly adherent quartz grains, not arranged in any 

 definite manner. These sometimes deeply indented the substance 

 of the tube and the body of the animal. The posterior end of 

 the animal apparently exercises some penetrating though not boring 

 function. 



The body of the animal varied much in diameter according to the 

 extent to which it was protruded. Under certain conditions, which 

 could not exactly be determined, the animals were greatly extended 

 from the tube. The body and tentacles were then mostly rigidly 

 extended. They sometimes slowly rotated in themselves — both 

 lophophore and body — but did not, as described for some species, 

 bend or wave from side to side. This latter movement was some- 

 times observed, however, when the animals were under observation 

 in small vessels, especially when being examined by transmitted 

 light. 



Tentacles, Muscular and Ciliary Movement, &c. — The method at 

 first adopted in microscopic examination of the living animals was 

 to remove it from its tube by cutting away the limestone, or to 

 suddenly cut off a protruded head, when after a time it often again 

 expanded fully. The tentacles were then observed to be well pro- 

 vided with long cilia (about one-fourth the diameter of the tentacles). 

 In these cases, however, the cilia were never observed to be in motion 



