Coccidosis 



A disease in poultry, rabbits, etc., caused by certain micro- 

 organisms (Sporozoa). 



Codominant 



One of two or more of the dominants in a community. 



Coefficient of Association 



A measure of the joint occurrence of any two species not 

 due to chance, obtained by dividing the number of samples 

 in which both species occur by the number of samples in 

 which it is expected they would occur only by chance. 



Coefficient of Community 



The ratio of the number of species common to two com- 

 munities or areas to the total number of species occurring 

 in each of the communities, cf. Index of similarity. 



Coefficient of Variation 



The standard deviation expressed as a fraction of the 

 mean, or as a percentage. 



Coelenterate 



An animal in the Invertebrate phylum Coelenterata, e.g., 

 corals, sea-anemones, jellyfish. 



Coelom 



The body cavity in many invertebrate and vertebrate 

 groups of animals. 



Coenobiology (Cenobiology) 



See Biocoenology. 



Coenobium 



A colony of organisms held together in a common sub- 

 stance, e.g., Volvox. 



Coenocline 



The sequence of natural communities in relation to 



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