Herrick, Cranial Nerves of the Cod Fish. 291 



Those branches of the r. lateraHs accessorius which run 

 back under the skin in tlie neighbood of the supra-temporal 

 canal enter a cutaneous area which also receives numerous very- 

 delicate nerves from the vagus. These latter are partly general 

 cutaneous and partly lateralis fibers from the r. supra-tempor- 

 alis vagi for pit-organs. The twigs from the r. lateralis acces- 

 sorius effect minute terminal anastomoses under the skin with 

 both kinds of vagal twigs, so that the innervation of this whole 

 region is exceeding difficult to analyze. 



I find a row of large pit-organs just in front of the supra- 

 temporal canal and approximately parallel with it, which evi- 

 dently corresponds to the organs figured by Cole in the same 

 position. They are innervated by coarse fibers from the r. 

 supra-temporalis vagi (Fig. i, st. X.). I have also found the 

 row of four or five pit-organs figured by Cole on his figure I, 

 running from the region of the supra-temporal canal back near 

 the median line to the beginning to the dorsal fin. They are all 

 supplied by nerves arising from the dorsal branch of the r. lat- 

 eralis vagi, leaving that nerve in connection with the twig for 

 the sixth organ of the lateral line of the trunk (Cole's nomen- 

 clature). This nerve is evidently the one marked L'' on Cole's 

 Fig. 2. It runs up and crosses the lateralis accessorius, run- 

 ning internal to its ventral branch and external to its middle 

 branch and very closely joined to them. 



In the region of the supra-temporal canal the r. lateralis 

 accessorius divides into three branches. The dorsal one is des- 

 tined for the base of the dorsal fin, the middle one for the base 

 of the anal fin and the ventral one for the paired fins. The 

 dorsal one sends first several small twigs up under the skin 

 toward the median line and then breaks up into an open plexus 

 which passes up and joins the branches already given off. The 

 larger of these branches are gathered near the mid-dorsal line 

 in the inter-muscular septum between the interspinal and the 

 general dorsal muscles. This nerve is therefore formed very 

 much as in Menidia, though the plexus formation at its origin 

 is extra-cranial instead of intra-cranial. The anastomosis with 



