382 WILLIAM A. HILTON 
fibers are recognized in the deeper layers. Some of the fibers are 
from the epithelial cells at the surface. The nervous tissue 
follows the epithelium up into the lophophore and into the tenta- 
cles. Two longitudinal nerve tubes or nerve bands are described 
running the length of the body. He suggests that these bands 
may give the appearance of tubes, due to shrinkage. Epithelial 
tissue seems to make up these strands, and he did not think they 
looked like nervous tissue. The suggestion is made that these 
so-called nerves may be sense organs. 
Seylys-Longchamps (07) describes the nerve band and the 
lateral nerve of Caldwell on the left side. 
Torrey (711), in Phoronis pacifica, gives a similar account of 
the nervous system with the following exception: 
‘The two longitudinal cords which are of exceedingly unequal 
length, instead of crossing in the nerve ring of the lophophore, 
are continuous across the middle line at the level of the median 
mass of ganglion cells. The loop thus formed is closely applied 
to the latter and touches the lophophore nerve on each side of 
the rectum, apparently without fusing at either point.” 
Pixell (12) in P. vancouverensis, describes the usual band 
of nerve tissue at the base of the lophophore and the nerves up 
into the tentacles. He mentions the large ganglionic mass on 
the dorsal surface with the nervous tissue at all places in intimate 
relation to the inner ends of epithelial cells. In some sections 
he finds two small lateral nerve cords along the right and left 
sides of the body. These he says are short and composed of 
‘punctated’ substance. 
Nervous tissue was found in the center of the pit at the proximal 
end of the body and also along the alimentary canal on the outer 
side of the epithelium, especially in the region of the oesophagus 
opposite the nerve ring. This area has been suggested as an organ 
of taste. 
In Phoronapsis hameri a similar condition of the nerve ring 
was described, but the ring is narrower and more elongated. 
There is a conspicuous cord down the left side. Its center is 
clear and on its border nerve cells are described. 
Harmer (’17), in Phoronis ovatus, gives the position and 
form of the nerve ring which is thickened on the dorsal side. 
