91 O 



EENEST WARREN. 



("3'^) Colonies with the average arrangement of four in 

 an oral verticil, and five in a basal whorl. Observed six 

 times (about 14 per cent.). 



("4") Colonies with a vertical of four oral tentacles alter- 

 nating with a basal whorl of four tentacles. This is the 

 perfectl}^ symmetrical condition. Observed twenty-nine times 

 (about 69 per cent.). 



Text-fig. 7. 



Degree of symmetry (i 1 2 3 4 



Diagram showing distribution of symmetry in forty-two colonies. 



It must be remembered that these degrees of symmetry 

 may not be of equal value, although they are thus represented 

 in the diagram. For example, there may be a step where 

 the basal verticil has been reduced to four tentacles, but 

 these have not acquired the regular alternating position with 

 the oral tentacles. This cannot be observed with any great 

 certainty under the microscope. 



The results of this investigation may be summed up in the 

 following paragraphs : 



(1) The amount of material available is not sufficient to be 

 certain as to whether locality or sex have any effect on the 

 arrangement of the tentacles. 



