166 JULIA WORTHINGTON. 
twigs to innervate the lateral face of the tube, while the rest 
goes on to the skin, innervating it in the extreme anterior 
dorsal head region, near the roots of the first and second 
tentacles. R. ophthalmicus profundus also runs forward, 
lying between mm. palato-ethmoideo-superficialis and 
palato-ethmoideo-profundus. On nearing the anterior 
end of the head it turns dorsad, piercing the former muscle, 
and dividing into small ramuli, supplying the skin around 
the nasal opening, and the second tentacle. The innervation 
of the first three tentacles is practically the same. The nerve 
enters in one or two large branches and immediately sub- 
divides into several fine ones that fill the entire space between 
the cartilage core and the skin. These branches li so close 
together that in longitudinal sections there seems to bea 
solid nerve mass surrounding the core; and it is only in 
cross sections of the tentacle that the nerve mass is seen to 
consist of fine ramuli, running in converging lines toward 
the tip. 
Truncus Maxillo-Mandibularis.—This great division, 
containing both sensory and motor fibres, on leaving its own 
part of the Gasserian ganglion, divides quickly into four 
branches, two of them belonging to the r. maxillaris, and 
two tothe r. mandibularis. R. maxillaris anterior 
(Fiirbringer’s r. anterior maxillaris externus) is a 
broad, stout trunk, ranning forward beneath the sub-ocular 
arch, and through m. palato-coronaris, where it divides 
into a superficial and a deep branch. The superficial branch 
runs forward between m. palato-coronarisand m. copulo- 
quadratus-profundus, dividing at the anterior end of the 
latter muscle into four branches. Of these the outer and 
smaller is purely motor, supplying m. copulo-palatinus, 
the others are sensory, supplying the first, third, and fourth 
tentacles, and the skin immediately around them. The 
nerve of the first tentacle is particularly rich in small skin 
rami. The fourth tentacle is different in shape from the 
other three. They have narrow bases and taper to a sharp 
point, while the fourth, which is really a fold of the lip, has a 
