1028 



MISS K. HARRISON AND PROF. S. J. HICKSON ON 



94 septa, but here the arrangement is not so simple : in one lateral 

 chamber on each side between the primary and secondary septa 

 the fifth cycle is unrepresented, there being only three instead of 

 the normal seven septa. On the other hand, in both the apical 



Text-fig. 217. 



Dla^r.in ni tic plan of the sepfe of Faracyathus cavatus. The primary and 

 secondary septa are black, the tertiaries are cross-hatched, the quaternaries are 

 crossed with diagonal lines, the quinaries are left blank ; i, ii, iii, iv, v, septa 

 of the first, second, third, fourth, and fifth cycles. 



chambers at one end of the long axis there is an excess of septa. 

 In both chambers, between the primary and secondary septa on 

 the one side, and the primary and secondary septa on the other 



