724 Teds. [VoL. XII. 
nerve were seen going to either of the other two branches of 
the ventral root, but they may nevertheless exist, as in the 
chick (von Lenhossék), for my sections not being especially 
prepared for such work, I made no special search for them. I 
also did not attempt to find whether the small communicating, 
or anterior, branch of the nerve arose from the dorsal or from 
the ventral root. This communicating branch in young larvae 
runs directly forward instead of upward and backward as in the 
adult. The sympathetic ganglia did not lie, as in the chick, 
upon the ventral branches of the ventral roots. From the dorsal 
end of the spinal ganglion, in some sections, there was a dorsal 
prolongation and possibly also a delicate dorsal branch. I could 
not, however, trace the latter either in larvae or in the adult. 
The spinal nerves in Amia thus seem to differ considerably 
from the schema given by Hatschek of the nerves in Amphi- 
oxus (No. 54, p. 140). 
The nervus postoccipitalis, or first spinal nerve, agrees in 
every respect with the other spinal nerves, and in front of it 
there are still two nerves (oc4 and o0c3, Figs. 33-35, 63, and 
64, Pls. XXVIII, XXIX, XXXVII, and XXXVIII) also agree- 
ing in every respect with those nerves. They issue and lie, 
one in front of each of the two occipital arches, and are 
described by Sagemehl (No. 104, p. 193) as occipital nerves. 
Sagemehl, however, did not find, or at least does not mention, 
the ganglion found on the dorsal root of each of them. In 
front of these two, complete, spinal-like, occipital nerves there 
are two ventral roots (oc? and oc!), one of which, the posterior 
one, is described by Sagemehl as the first occipital nerve. The 
other he did not find, nor did he find the foramen by which it 
issues from the skull. No other still more anterior nerve 
being found, I have called these nerves the first and second 
occipital nerves. As they belong, as will be shown later, to 
the second and third occipital muscle segments, they might, 
perhaps with better reason, be called the second and third 
occipital nerves. From each of them arise the dorsal, hori- 
zontal, and ventral branches found on the ventral roots of all 
the spinal nerves. The small, anterior, communicating branch 
found on all the spinal nerves was not, however, found on them. 

