CHESTER. — STRUCTURE OF PSEUDOPLEXAURA CRASSA. 



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expanded stand at rifjht an<j;les to the hranehes, and are erowded, the 

 e()h)ny in this (•()n(hti()n looks hke a miniature h'afless shrub witli 

 unusually thick hraneiies; because the tip is often bare of polyps 

 or these are there contracted, the colony when seen at a distance 

 below the surface may resemble very superficially a huge compound 



Fig. A. Young colony of Pseudoplexaura crassa, showing method of 

 branching and the calycle openings in the coenenchyma. 



tube sponge. But Figure A, although it shows the character of the 

 branching, does not show the great number of branches, or whips, 

 that occur in larger forms. As found on the Bermuda reefs, the species 

 varies greatly in size. A small colony stood 90 cm. high, its terminal 

 60 branches spreading over a circle 60 cm. in diameter. Another 



