No. 3.] LATERAL LINE OF AMIA. 477 
already referred to. The posterior branch of this system is 
continued as a groove onto the outer surface of the first sub- 
orbital. 
Leaving the lachrymal, the canal passes through the middle 
of the two suborbitals, and enters the lower postorbital near its 
lower anterior angle. Running upward and backward in this 
bone, to about one-quarter its length, the canal turns directly 
upward, traverses the rest of the bone, and enters the upper 
postorbital at the anterior quarter of its lower edge. Turning 
somewhat forward here, it passes through this bone, turning 
directly upward again and then backward, just as it leaves it, 
to enter the postfrontal. 
In its course through the sub- and postorbitals, the canal 
gives off the trunks of seven peripheral systems. The first one, 
trunk 10, leaves the main canal near the hind end of the first 
suborbital. Dividing immediately, it sends one branch forward, 
with five large openings near the lower edge of the bone, and 
one backward, ending in a groove on the anterior end of the 
outer surface of the second suborbital, making six openings in 
all, three of which at least are double. Trunk 11 is given off 
upward and outward near the hind end of the second suborbital. 
It sends one branch forward along the outer edge of this bone 
toward the end of the branch from trunk 10, and another 
backward into the lower postorbital, the two branches having 
sixteen openings in all, five, three of which are double, being 
in the suborbital, and eleven single ones in the postorbital. 
Trunk 12 leaves the canal where it turns directly upward at 
about the middle of its course through the lower postorbital. 
It is directed downward and backward, and gives off several 
branches, each of which divides again one or more times, the 
longer branches lying mostly parallel to the main trunk. It has 
in all thirty-seven openings, which lie in a group a little in front 
of and below the middle point of the bone. Trunk 13 is short, 
and is given off just as the main canal enters the upper post- 
orbital. It divides immediately, sending one branch, with eight 
openings, downward and backward into the lower postorbital, 
and another, with twelve openings, upward and backward into 
the upper postorbital, making twenty openings in this system. 
Trunk 14 is given off at about three-quarters of the course of 
the canal through the upper postorbital, the bone here being 
