No. 3.] LATERAL LINE OF AMIA. 489 
edges of the lachrymal and first suborbital, and over the lower 
edge of the second suborbital and the lower anterior corner of 
the lower postorbital, fitting into a depression on the outer sur- 
face of these two bones. The lower edges of the lachrymal and 
first suborbital, and the upper edge of this depression from the 
upper edge of the furrow, which is continued a short distance 
downward and backward behind the maxilla along the hind 
edge of the mandible. In young specimens the edge of this 
furrow, which may be called the supramaxillary furrow, is 
straight, and the pores of groups 8 to 11 are closely arranged in 
a line along it; but in the adult it is strongly ogee-shaped, and 
many pores may lie above the marginal row, especially immedi- 
ately below or just in front of the eye. Group 12, which is 
usually continuous with group 11, lies immediately behind the 
maxilla, near the lower edge of the lower postorbital, and often 
extending beyond it. It is usually continuous with groups 13 
and 14, which lie above and before it, directly behind the eye, 
superficial to the postorbitals and below the lateral edges of the 
postfrontal and squamosal. In these eight groups, Nos. 7 to 14 
inclusive, there were in the 17-inch specimen one hundred and 
two pores, and in the 27-inch one, three hundred and thirty- 
three. In the 20}-inch male, either system 13 or 14 was want- 
ing (probably No. 13), a condition frequently found, and there 
were accordingly only one hundred and one pores in groups 7 
to 14, while in the skull, where the number of groups was nor- 
mal, there were one hundred and forty-nine openings. 
The pores of the double system, infra-orbital 15, supra-orbital 
7, and those of group 16 infra-orbital, form a continuous line, 
extending from immediately above and behind the eye, nearly 
to the front edge of the extrascapula, which edge lies in line 
with the upper end of the pre-opercular fold. Some of the 
pores of these two groups extend laterally beyond the edges of 
the postfrontal and squamosal. In the 17-inch specimen there 
were eighty-nine pores in the two groups; in the 201-inch one, 
seventy-eight ; and in the 27-inch one, two hundred and eighty- 
eight. In the skull there were eighty-two openings. 
Groups 18 and 19, and group 3 of the supratemporal commis- 
sure, form one large surface group. Groups Ig and 20, and 20 
and 21, are also more or less continuous, but easily distinguish- 
able, as seen in the figures. Groups 18 and Ig infra-orbital 
