AUTHOR’S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE, SEPTEMBER 13 
ACTIVITIES OF COLONIAL ANIMALS 
Il. NEUROMUSCULAR MOVEMENTS AND PHOSPHORESCENCE 
IN RENILLA! 
G. H. PARKER 
TWELVE TEXT FIGURES AND ONE PLATE (EIGHT FIGURES) 
INTRODUCTION 
Although Renilla possesses two well-defined colonial move- 
ments, both of which may be associated with a certain amount of 
locomotion, neither of them seems to have excited the attention 
of investigators to any marked degree. This is probably due to 
the fact that few workers have had the opportunity of studying 
living animals. The two movements referred to may be desig- 
nated as peduncular peristalsis and rachidial peristalsis. These 
movements, which make up a large part of the general activities 
of Renilla, have been vaguely noted in various sea-pens by a 
number of workers (Verrill, ’64, p. 13; Musgrave, ’09, p. 459), 
who, however, have not sharply distinguished them. From the 
accounts given it is clear that rachidial peristalsis in Renilla was 
seen by Miiller (’64, p. 354) and by Eisen (’76, p. 18) and pedun- 
cular peristalsis by Wilson (’83, p. 784), who showed the rela- 
tion of this activity to locomotion especially in young animals. 
Aside from these few references, however, past publications 
contain almost no mention of these activities. I shall consider 
them separately, beginning with peduncular peristalsis. 
PEDUNCULAR PERISTALSIS 
The extended peduncle in a large individual of Renilla amethys- 
tina may measure as much as 7 to 8 cm. in length. In R. reni- 
- formis, as Agassiz (’50, p. 208) observed, the peduncle may 
1 Contributions from the Zodlogical Laboratory of the Museum of Comparative 
Zoédlogy at Harvard College, no. 325. 
475 
