48 



ME. P. II. CAEPENTEE ON THE GENUS ACTINOMETEA. 



Table IV. — Showing the Variation in the number of Segments in the 



first Interval. 



It is also seen in Table III. that even when the second syzygium is abnormally placed, 

 it is usually the case that the interval between it and the third is the normal one of three 

 simple segments, so that scries like 3, 9, 13 ; 3, 11, 15 ; and 3, 12, 16, are very common. 

 This is well seen in Table V., which shows clearly that the length of the second interval 

 is normally three segments ; that, like the first, it tends to vary in the direction of excess 

 rather than of defect, and that the range of variation in both directions is greater in the 

 varieties than in the type of Act. polymorpha. 



Table V. — Showing the Variation in the number of Segments in the 



second Interval. 



After the fourteenth brachial a syzygium usually occurs on every fourth segment ; so 

 that the number of segments composing the syzygial interval is normally three. It is, how- 

 ever, very unusual to meet with an arm in which this interval is constant throughout 

 its whole length and does not vary to a greater or less extent. In only seven arms out 

 of the whole number which I have examined have I found this to be the case, together 

 with normal first and second intervals, although twenty-three other arms were regular 

 from the second syzygium onwards. These thirty arms were distributed among five out 



