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latter bones there is a single sense organ, the eighth organ of the line 
lying in the posterior suborbital bone and the ninth organ in the post- 
frontal. The ninth pore of the line opens by a short tube into the 
canal near the dorsal edge of the posterior suborbital bone, the pore 
lying almost directly dorsal to the eighth pore, almost directly in the 
line of the dorsal edge of the eye, and immediately anterior to the 
rounded anterior edge of the series of prespiracular ossicles. It lies, 
like all the preceding pores, in the tough dermis that surrounds the 
eye and nasal apertures. 
The posterior suborbital bone is manifestly the homologue of the 
upper, or second postorbital bone of Amia. 
The tenth pore of the line opens by a short tube into the canal 
near the dorso-posterior end of the postfrontal, the main infraorbital 
canal here anastomosing with the hind end of the supraorbital canal. 
The pore lies in the line of tough dermis that covers the adjoining 
edges of the frontal bone and the series of prespiracular ossicles, lying, 
in this specimen, opposite the third ossicle counting forward from the 
anterior spiracular ossicle. Immediately posterior to this tenth tube 
the canal leaves the postfrontal and enters the parietal of TRAquair’s 
descriptions, that bone being here overlapped to a considerable extent, 
and covered externally by, the hind end of the frontal. The canal does 
not here enter the frontal bone at all, though that bone certainly 
takes some part in covering it as it passes from the postfrontal into 
the parietal, at least in 30-cm specimens where it was more parti- 
cularly examined. This is an important detail. CoLLINGE says that the 
canal here traverses a part of the frontal, as it in fact seems to do 
in external views of the skull. TRAQUAIR says that the canal passes 
from the parietal into the postfrontal, and then enters the frontal, he 
considering the supraorbital canal as the direct anterior continuation 
of the canal posterior to that point. The fact is that the canal 
does not enter the frontal at all, that bone simply forming the roof of 
a part of it, the frontal thus having, in this fish, the same secondary 
relation to the canal that it has in Amia, and also in Scomber (No. 6). 
In the parietal the canal runs almost directly backward to the 
hind edge of the bone, lying near its lateral edge. At about the 
middle of the length of the visible part of the bone, and a little post- 
erior to the middle of the spiracular opening, the eleventh tube and 
pore of the line are found. Between this tube and the tenth tube, in 
the parietal, and at about the level of the hind edge of the frontal, 
is the tenth sense organ of the line. Posterior to the eleventh pore, 
not far from the hind end of the parietal, is the eleventh organ of the 
