Growth, and Habits of Bijiorae. 3 



round the outside of it. Fi<;. 1 is a sketch made under the 

 cainei-a lucida of a section ; it, however, is somewhat imperfect 

 owintr to the veiy brittle nature of the coral, but it will be 

 seen that the coral started to grow upon the Biporu at a very 

 early stage of the hitter's existence. I have indicated the junc- 

 tion of the coral and the Bipord by a thick line. A charac- 

 teristic pointing to the same conclusion is that in these conical 

 forms the zooecia are, in almost every instance, in perfectly 

 regular rows from the apex to the base, they very gradually in-' 

 crease in size from the apex to the base, and the zoaria i^reserve 

 their shape throughout their growth — i.e., both the young and 

 the old zoaria have the same angle at the apex. 



As stated above, I consider the conical forms in their living 

 state have the base uppermost. This would seem to be in- 

 credible, but in a postscript to his paper Mr. Whitelegge men- 

 tions he had had the good fortune to have had a living speci-' 

 men of Bipora jilnlijjpinensis (a nearly flat form living in Port 

 Jackson) under observation for three days ; and that from it 

 there extended fine filaments, half an inch long, attached in 

 some cases to tubes of Annelids and fragments of shell. He 

 Bays the filaments appeared to grow out of an avicularium. 

 This affords a clue to the manner in which the conical forms 

 manage to live with their bases upwards. All of them have on 

 the apex small avicularia and pores, and I consider that from 

 these pores filaments similar to those recorded on Bipora 

 philij)pinensin grow, and probably attach themselves to frag- 

 ments of shells, etc., on the surface of the ocean l)cd. and so 

 anchor themselves. Professor Harmer, in his Presidential ad- 

 dress to section 1). of the British Association for the Advance- 

 ment of Science at Dublin, in 1!)(»S, stated he had some evidence 

 that Selenariidae (in which the Biporae were originally placed) 

 juay be attached to ooze by means of veiy delicate, flexible 

 rooting l»r(jcesses, and he has suggested to me that probably 

 these conical forms are attached by a ligament to some foreign 

 substancein the same way as Parmularia ohliqua, McG., is, and 

 that they hang downwards in the watci-. This is jiossibly the 

 case, but the ligaments may be strong enough to iiermit the 

 zoaria being sustained in an upright position, or in any position 

 between the vertical and horizontal. 



