52 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
right hand end of its dorsal surface. The cells near the 
aperture of the funnel are very large and distinct while 
the cilia they bear are long and numerous and he directed 
upwards towards the inner end of the funnel. That cecal 
end is supplied by a nerve. The central nervous system 
is here at its largest. It shows large granular nerve cells, 
and the otocyst (Pl. IV. fig. 6, 0.c.). The endostyle and 
the lateral oral glands are very much as before. 
Ten sections further forward, No. 266 (Pl. IV. fig. 7) 
we find the body still smaller. It 1s now close to the 
anterior end, and this 1s the last section we figure. The 
pharynx is now small and will shortly terminate in the 
oral aperture. The two large glands he alongside it, but 
the endostyle is no longer visible ventrally, we are in front 
of its anterior end. Dorsally the nervous system is seen 
attached to the inner surface of the ectoderm, where it 
extends outwards into two lateral processes. Figure 8 
shows this region more highly magnified (x 600). The 
ectoderm is here distinctly two layers thick, and is covered 
by a cuticle or test which can be traced as a distinct 
though thin layer completely round the body in this 
region. 
The nervous system, then, when traced through the 
whole series of sections is seen to be connected anteriorly 
with the dorsal ectoderm close to the mouth; then it 
becomes free from the ectoderm and expands to form the 
large ganglionic mass or brain placed above the front of 
the pharynx (see Pl. [V. fig. 9, ».s.) and having two sense 
organs, the ciliated funnel and the otocyst, connected with 
it. The ganglion then tapers posteriorly to form a slender 
nerve cord, the myelon, which runs backwards over the 
pharynx, rather on the right side of the medio-dorsal line 
(Pl. III. fig. 3), until it reaches the esophagus where it 
turns ventrally and runs down between the pyloric sac 
