48 ORGANIC DEPENDENCE AND DISEASE 



ILLUSTRATIONS OF PLEUEODICTYUM AND ITS COMMENSAL 

 WORM HICETES 



Figs. 22 and 23. Top and side views of the eorallum in its normal size and form. 



The apertures of the worm tube are shown at X. 

 Fig. 24. 'An etching whicli has the calcareous substance of the base of the coral 



removed and shows the initial convolutions of the worm tube. 

 Fig. 25. The under side of a eorallum with the impression of the gastropod 



Loxonema liamiltoniae to which it was attached. 



Fig. 26. The form of the entire worm tube drawn from an actual specimen. 

 Fig. 27. A shell of Loxonema liamiltoniae. 



Fig. 28. Vertical section of a eorallum, showing the convoluted worm tube. 

 Fig. 29. Enlarged surface of a Loxonema shell which had been the base of 



attachment for the coral. This specimen bears several serpulid worm tubes 



which were there before the coral began to grow. 

 Fig. 30. Section of the coral, showing tubes of more than one worm. 



