60 
ORGANIC DEPENDENCE AND DISEASE 
Fig. 48. Caunopora; a stromatoporoid colony showing the tubes of Syringopora, 
a coral that lived commensally with it. 
Fig. 49. Schematic section showing the structure of the coral tubes 
in the stromatoporoid mass. Onondaga limestone (Lower Devonian). 
currences and tliis association of tlie hydroid with the zoan- 
tharian corals is widespread. Other occurrences of this 
sort are well known and we figure here a colony of the 
honeycomb coral Favosites which has overgrown a small 
plantation of the cyathophylloid coral Amplexus. In all 
these associations there has been apparently no interfer- 
ence with the functions of either member of the combina- 
tions. Naturally, as these are merely incidents of their 
growth they have been carried onward into recent coral 
plantations where such combinations are not infrequently 
noted. 
