The Lateral Sensory System in the Muraenidae. 153 



passing to the left side of the membranes enclosing the end of the 

 cavity and the left one to the right of it, and both soon ending there. 

 The small vessel that comes from the ethmoidal sensory chamber, and 

 that here lies on the left side in the sections, joins the vessel that 

 accompanies the nerve on the right hand side of the sections. There was 

 no noticeable connection between either of these three vessels and 

 either the arterial or venous systems of the fish. 



Just what the significance of these several bloodvessels of Conger 

 may be, I can not determine, but it seems a noteworthy fact that the 

 two large ones arise in connection with the sensory epithelium of the 

 nose, quite generally supposed to be of lateral sensory oiigin, and the 

 small one in the same relation to definite lateral sensory tissues enclosed 

 in a median cavity in the end of the snout of the fish. That the sensory 

 tissues of this median cavity are related, morphologically, to the 

 tissues of the median nasal sac of Myxine could only be possible if 

 their innervation was similar, and this seems impossible. The sug- 

 gestion can not, however, but present itself, as also the possibility of 

 the cartilage-tipped processes that transmit the lateral sensory tubules 

 having some relationship to the so-called "cirri" of Paleospondylus. 



Supraorbital canal. 



The supraorbital canal begins anteriorly at a pore that lies dorso- 

 antero-mesial to the dorsal edge of the base of the nasal tube. It 

 lies directly dorsal to the anterior pore of the ethmoidal canal, and, 

 like that pore, lies immediately lateral to the latero-rostral fold on 

 the end of the snout. The pore leads into the anterior terminal tube 

 of the line, which runs at first backward and slightly mesially and 

 enters the anterior end of the nasal bone, close to its mesial edge. 

 Before it becomes entirely enclosed in this latter bone it is joined by, 

 and anastomoses completely with, the posterior end of the ethmoidal 

 canal, the point of anastomosis lying at the extreme base of the 

 anterior supraorbital tube and but slightly anterior to the first supra- 

 orbital sense organ. 



In the nasal the supraorbital canal continues almost directly 

 backward, first turning gradually and very slightly laterally and then 



