170 JULIA WORTHINGTON. 
consisting sometimes of a compact group of cells, forming a 
cluster about twice the diameter of the nerve, and sometimes 
having its cells lying singly, embedded in the nerve cord. 
After leaving the ganglionic region the facial nerve con- 
tinues caudo-ventrad until it reaches the anterior border of 
the crani-hyo muscle, into which it sends a small twig. 
Then turning, the nerve runs caudo-cephalad, curving over 
the hyoid arch, and courses cephalad on the mesial surfaces 
ofmm. copulo-quadratus-profundus, and hyo-copulo- 
palatinus. It innervates the second of these muscles, but 
the innervation is hard to find, for instead of sending in the 
usual nerve twigs to subdivide in the heart of the muscle, it 
sends the fibres in as clusters of separate threads, and they 
are lost almost immediately. I have not found, either in 
sections or in dissecting, any twig answering to Fiirbringer’s 
r. cutaneus. While running on the inner surface of m. 
hyo-copulo-palatinus, the facialis divides into two 
or three branches, the dorsal branch carrying the motor 
fibres. There is nothing fixed as to the level of this division 
or the number of branches, the nerves of opposite sides 
differing sometimes in the same head. The branches turn 
ventro-laterad, passing between m. hyo-copulo-palatinus 
and m. copulo-palatinus, and forward over the latter 
muscle to the skin. They are so very small that I have not 
been able to trace them definitely to their endings in the 
skin, but I have every reason to believe that they terminate 
in the region of the fourth tentacle. I have found no 
communicating branch between the facialis and the 
trigeminus, or between the facialis and the glosso- 
pharyngeus. 
The Nerves of the Lateral Line.—These two nerves, 
acusticus @ and acusticus b, it is more convenient for 
purposes of comparison to consider together, for they repre- 
sent in Bdellostoma what Johnston, 1902, calls the “ lateral 
line VII” of Petromyzon, and Strong, 1895, the ‘ dorsal 
VII” or “VII 6b” of Amphibia. The position of these 
nerves in Bdellostoma is exceedingly interesting, for here 
