Stuckey. — A Review of the New Zealand Actiniaria. 



391 



C. gracilis : The mesogloea of the column contains a single row of spaces, 

 more or less round. This feature, however, may prove to be the result of 

 treatment. 



C. mollis : The mesogloea is very slightly fibrous. The stomodaeum is 

 much folded, and into it run processes of the mesogloea. The musculature 

 of the mesenteries is stronger than that of the other species. 



C. albida : As in C. mollis, the stomodfeum is much folded, and has 

 mesoglceal processes projecting into its ectoderm. Each of these processes 

 is opposite to the attachment of a pair of mesenteries. The outer parts of 

 the mesenterial spaces are filled with hypertrophied endoderm. 



Reproduction. — No gonads appeared in any of my sections, but masses 

 of ova and young animals appeared in the bowl with the animal that divided 

 in the manner to be described below. This was a specimen of C. haddoni 

 taken on the 31st August, 1908. It was on a small stone, and attracted 

 attention on account of the fact that it had spread itself out in the form 

 of a flattened elliptical disc, the length of which was four or five times the 

 diameter of an ordinary specimen, while the breadth was half the length. 

 It was so flattened that the oral and pedal discs were almost in contact. 

 The mouth gaped wide, having been stretched in the same way as the body. 



© © 



VII 



Fig. 12. 



The mesenterial filaments were plainly visible. The tentacles were almost 

 completely retracted, only the knobs showing. The animal, on its stone, 

 was placed in an aquarium, and closely watched. In two or three days 

 the wall became thin at one extremity of the minor axis of the ellipse, finally 

 splitting at that point. The free ends began to retreat, as it were, in a 

 direction parallel to the major axis. As they approached the vertices of 

 the ellipse they began to curl inwards. A second split occurred about the 

 place marked x in the diagram, and the first daughter organism became 

 free. The two ends gradually curled round, and finally coalesced. In the 

 meantime the last-freed ends began to curl inwards, and another split began 

 to form at the place marked y. The second and third daughter organisms 

 closed up as the first had done. Thus three organisms were formed by a 

 process of fission, which I have called " lateral fission." The whole process, 



