PRESIDENTIAL ADDRESS. 



65 



... , 



Fig. 30. Tube of the reef 

 building annelid worm, Galeo 

 laria ccespitosa, natural size. 





very solid and keeled, the keel projecting as a spur over 

 the orifice (fig. 30). When the tide falls, the animal shrinks 

 jg&. w far down and blocks the opening 



by a thick lid, thus enduring long 

 exposure to dry air and hot sun. 

 But beneath the water, the worms 

 are bold and active, under the 

 microscope the branchiae project 

 as coiled wreaths, 

 while to the naked 

 eye, the waving 

 plumes lend to the 

 mass of stone a 

 coat of fur (fig. 31). 

 There is an odd 

 local tradition 

 that Galeolaria is 

 not indigenous 

 here, but was in- 

 troduced from 

 abroad many 

 years ago. Perhaps this refers to some periodic fluctuation 

 of rarity and abundance. 



The Galeolaria is intolerant of sand or mud, its limit is 

 the range of the neap tides, and it occurs both on the surf- 

 swept headlands and on the wharf piles in sheltered water. 

 In places a mass of intertwined shells forms a crust upon 

 the rocks, six or eight inches thick. So continuous is it 

 that the rocks appear from a distance as if painted white. 

 Such a crust slightly resembles coral in its flowing contours, 

 but rough surface; it deepens and narrows the original 

 cracks and pools among the rocks. An example of such 

 development selected for illustration is Wyargine Point at 

 the south entrance to Middle Harbour. (Plate V, fig. 9). 



E— May 5, 1915. 



Fig, 31. Galeolaria c&s 



extruded from its 



tube with the branchiae unfurled, magnified. 



