80 
The mandibular canals unite at the symphysis of the mandibles, 
and a single median pore is there found. 
The main infraorbital canals unite on the top of the snout, there 
being enclosed in a purely dermal, median, ethmoid bone. The pri- 
mary tube and pore that should have normally been formed, in the 
median line, where the canals of opposite sides unite, has disappeared, 
as in Amia. 
The supraorbital canal does not anywhere connect directly with 
its fellow of the opposite side, but it anastomoses both anteriorly and 
posteriorly with the main infraorbital canal. The anterior anastomosis 
is formed by the fusion of the second tube and pore of the line with 
the second tube and pore of the main infraorbital line. The posterior 
anastomosis is formed by the fusion of the seventh, or posterior ter- 
minal pore of the supraorbital line with the tenth pore of the main 
infraorbital line. 
The supratemporal commissure connects, in the median line, with 
its fellow of the opposite side, and is the strict homologue, if its inner- 
vation has been properly given by POLLARD, of the cross-commissure 
of Amia. Its lateral, terminal pore fuses with pore 12 infraorbital to 
form a double pore. 
The preopercular canal is continuous with the mandibular canal, 
but it does not join, at its dorsal end, the main infraorbital canal. 
Anterior and middle dorsal head lines of pit organs are found, 
as in Amia, but no indication could be found of a posterior head line. 
The anterior and middle head lines correspond closely, but not ex- 
actly, in position with the similarly named lines in Amia. 
There are horizontal and vertical cheek lines of pit organs, and 
a gular line of pit organs, as in Amia, but no trace of the mandi- 
bular pit line of that fish could be found. 
There are three sensory lines on the body of the fish, the more 
important one of the three having the most ventral position and cor- 
responding, apparently, to the main lateral line of other fishes; while 
the most dorsal one apparently corresponds to the dorsal body line 
of Amia and certain other fishes. The third line lies between the other 
two, is less complete than either of them, and may, perhaps, corre- 
spond to the accessory lateral line of Amia. 
Menton, Palais Carnolés, 
March 15th 1900. 
Literature. 
1) Acassız, Louis, Recherches sur les Poissons fossiles. Neuchatel, 
1833/34. 
