266 Vniversity of California Puhlications. [Zoology 



grams show that the distal tentacles tend to appear before the 

 proximal. The first two arise simultaneously and opposite or 

 nearly so in ten among thirteen cases (77 per cent.) ; the first 

 four may arise simultaneously, as in (1) ; occasionally the proxi- 

 mal set may begin before the distal, as in (9). The members 

 of the proximal set have no definite position relatively to the 

 members of the distal set of corresponding age, although, as in 

 (2) and (3), they may sometimes arise in the same plane. The 

 first two proximal tentacles are opposed in four among fourteen 

 cases (28.5 per cent.), showing a less tendency to regularity 

 than the distal tentacles. 



The following is a tabulation of the number of tentacles in 

 distal and proximal sets in fifty-five individuals whose develop- 

 ment in most instances was not observed. 



Dist. 







2 



3 



3 



3 



3 



3 



3 



4 



4 



4 



4 



5 



5 



5 



5 



5 



6 



G 



7 

 12 

 15 

 15 

 17 



The diagrams and this table, taken together, show that while 

 distal tentacles appear, on the whole, earlier than the proximal, 



