No. 3.] MUSCLES AND NERVES IN AMIA CALVA. 577 
by McMurrich as the anterior portion of the adductor arcus 
palatini, and is said by him to be innervated, as the posterior 
portion of that muscle is, by a branch of the facialis. But for 
this innervation this muscle would certainly seem to be the 
third or fourth division of the levator maxillae superioris of 
Amia, for both in its origin and insertion it differs but little 
from and could easily be derived from that of those muscles. 
Pollard says (No. 97, p. 390) that the motor nerves to the cor- 
responding muscle in Auchenapsis ‘run along with the pala- 
tine nerve,” the palatine nerve referred to being described as a 
branch of the trigeminus. Pollard further states, as a general 
principle, that the motor supply of all the tentacle muscles in 
siluroids must be by nerves that “ proceed out with the sensory 
nerves”’ of the tentacles (No. 97, p. 382). This general state- 
ment shows, what Pollard does not otherwise definitely state, 
that he found all the tentacle muscles in all the fishes he exam- 
ined supplied, as the tentacles themselves are said to be, by 
branches of the trigeminus. The innervation of the muscle 
in Amiurus may therefore be by the trigeminus instead of by 
the facialis, as McMurrich states, in which case it is certainly 
the homologue of the third and fourth divisions of the levator 
maxillae superioris. 
In the Marsipobranchii Add is represented probably in the 
group of muscles that in Mixine are innervated by the so-called 
r. ophthalmicus trigemini, and to the muscles that in Petromy- 
zon are associated with the “ Vorknorpel”’ and innervated by 
the r. maxillaris trigemini (No. 37, pp. 34 and 40). The r. oph- 
thalmicus trigemini in Mixine, according to Fiirbringer (No. 37, 
p. 71), gives off a sensory branch which runs forward above the 
optic nerve and then itself runs under that nerve, giving off 
both sensory and motor branches, the motor branches going to 
the muscles of the tentacular circle and the nasal tube. In 
Petromyzon the r. ophthalmicus trigemini is said to be entirely 
sensory, and runs over the optic nerve, as does the first sensory 
branch of the nerve in Mixine (No. 37, p. 62). In Bdello- 
stoma also the main trunk of the nerve runs over the opticus, 
but whether it contains motor fibres or not Fiirbringer does 
not state (No. 37, p. 31). The ophthalmic nerve in Mixine 
