292 Journal of Comparative Neurology. 



the dorsal rami of the successive spinal nerves occurs in the 

 typical way. 



In the region of the pectoral girdle where the dorsal branch 

 of the r. lateralis vagi becomes superficial the accessory lateral 

 line nerves cross the lateralis vagi. In regard to the relations 

 of these nerves, I confirm the figure of Stannius ('49, Plate 

 III, Fig. 2). The middle and ventral branches of the acces- 

 sory nerve embrace the dorsal lateral line nerve without anasto- 

 sing with it, one going external, the other internal. The branch 

 for the anal fin takes the internal course, but some of these 

 fibers separate from this nerve and later join the branch for the 

 paired fins. All of the accessory lateralis fibers anastomose 

 more or less in this region with medial rami of the spinal nerves. 

 The nerve for the anal fin crosses the ventral branch of the r. 

 lateralis vagi externally. It was not traced to its termination. 



The nerve for the pectoral fin is small. It joins the bra- 

 chial plexus and its fibers could not be separately followed into 

 the fin. 



The nerve for the pelvic fin is much larger. It enters that 

 fin in two branches in connection with spinal nerves, one branch 

 at the cephalic and one at the caudal end of the attachment of 

 the fin. The accessory lateralis fibers could not be followed 

 separately from the spinal nerves. 



The pelvic fin is sparsely covered at the angles, particularly 

 the outer edge, with very minute terminal buds. These do 

 not at all resemble the "pit-organs " of the head, as I have 

 found them in these same specimens. The latter are broad 

 and flat topped. They are not in fish of this age sunken 

 into pits, but exposed upon the skin and slightly projecting 

 above it, just as in the adult of Menidia, They extend down 

 through the epidermis to rest upon the dermis, which is often 

 thinner under them and raised up into a ring-shaped elevation 

 projecting up into the epidermis around the border of the 

 organ. This area of dermis is perforated in its center for the 

 nerve. The nerve fibers are of medium size and very densely 

 myelinated, so that they stain intensely. 



These terminal buds of the fins, on the other hand, are 



