NERVOUS SYSTEM OF PHORONIDA 383 
I have had opportunity of examining a considerable number of 
two species of this interesting group. One, Phoronis pacifica, 
occurs at various places off the coast of southern California, 
where it has been obtained and examined during three summers. 
The other, a species of Phoronapsis, has been obtained during 
two years at Monterey Bay and one year at Moro Bay. Both 
species were studied in serial section. In spite of the occasional 
difficulty with sections due to the presence of sand grains, a 
number of perfect series was obtained. Phoronapsis also was 
observed in the field at Monterey and through the kindness of 
Doctor Fisher at the Hopkins Marine Station at Pacifie Grove. 
These forms were also encountered in even greater numbers at 
Moro Bay. 
The animals do not have many activities. In quiet waters 
the tentacle whorls are fully expanded just above the surface of 
the sand. Shadows or bright light seem not to affect them in 
such positions. Moderate movements in the water made by a 
pipette near caused them to change their positions. Sand grains 
dropped gradually upon the expanded tentacles produce little 
or no contraction. Touching the tentacles seemed not to bring 
about any marked movements, but if the surface was lightly 
touched just below the whorl of tentacles there was an immediate 
and violent reaction and the animal may withdraw within its 
sandy tube. Any jarring of the sand supporting the sand tubes 
may also cause this contraction of tentacles and the withdrawal 
of the upper portion. 
In the laboratory the movements of Phoronapsis were found to 
be as follows: 
1. A contraction of the tentacles and a shortening of the 
animal. This is noted whether the animal is inclosed in its 
sand-grain tube or entirely outside. 
2. When out of the tube the whole stem may be waved about. 
Within the tube the bending is limited to a small area near the 
tentacles, but outside the tube all parts of the body are capable of 
bending. 
3. Slow contractions when the animal is stimulated outside of 
its tube. 
