136 Edward Phelps Allis jr., 



cavity ill this part of the skull, in which it douhtless anastomoses 

 with its fellow of the opposite side, and then turns forward; or for- 

 ward and slightly downward, and meets and anastomoses with the 

 anterior end of the supraorbital canal. A double primary tube and 

 pore are here formed, the pore lying mesial to, and close to the 

 dorsal edge of, the anterior nasal tube. 



The supraorbital canal, beginning at the double pore above 

 mentioned, runs backward and enters at once the nasal bone which 

 it traverses its full length, the hind end of the bone lying nearly in the 

 transverse level of the hind edge of the eye. As the canal traverses 

 the nasal, two primary tubes arise from it, one opening on the outer 

 surface by a single pore that lies on the top of the snout slightly 

 posterior to the anterior nasal tube, and the other being a blind pouch 

 that lies directly dorso-mesial to the eye. A second blind pouch 

 arises from the canal at the hind end of the nasal, the base of the 

 pouch being wholly enclosed in the nasal. Leaving the nasal the 

 canal enters the skull, runs ba^pkward in it a short distance and then 

 turns latero-postero-ventrally and anastomoses with the main infra- 

 orbital, as already described. At the bend in the canal a primary 

 tube arises, and running mesially and but slightly backward meets 

 and anastomoses in the middle line with its fellow of the opposite 

 side, a large median blind pouch here being formed. 



Conger conger. 



In Conger conger, and also in Ophicthys and Myrus, the adductor 

 mandibulae muscle extends upward, through nearly its entire width, 

 to the mid-dorsal line of the head, where it arises, in common with 

 its fellow of the opposite side, from a median vertical aponeurosis. 

 Posteriorly, this supracranial part of the adductor arises from the 

 anterior surface of a similar but much stronger and tougher aponeu- 

 rosis which arises from the hind end of the skull. This latter aponeu- 

 rosis extends directly outward, or outward and backward, between the 

 adductor and the anterior edge of the trunk muscles, to the ventra 

 surface of the tubular ossicles that enclose the supratemporal com- 

 missure. From these surfaces of origin, and also in part from a 



