PROFESSOR OWEN ON THE EUSTACHIAN CANALS IN CROCODILES. 
527 
Fig. 6. The opposite side of the same section, showing the median bony Eustachian 
canal, e, the lateml membranous Eustachian canals, el, cut off where they 
join the lateral bony canals, and the pterygoid air-cells, pt, communicating 
with the posterior nares, n, n. 
Fig. 7- A section of the cranium of the Crocodilus aciitus, showing the course of the 
median Eustachian canal, e, to its bifurcation at e’, the division of the basi- 
occipital branch, d to eo ; the course of the left lateral Eustachian canal, eV , 
to its communication, at the rhomboidal sinus, eo', with the tympanic branch 
of the basioccipital division of the median Eustachian canal. 
PLATE XLJI. 
Fig. 8. A vertical section of the cranium of the Crocodilus biporcatus, a little to the 
left of the median line, showing part of the left tympanic branches, es, eo, 
and the orifices, es', eo', of the right tympanic branches, of the primary 
divisions of the median canal, e' to e. 
Fig. 9. A vertical median section of the cranium of a Gavial, Gavialis gangeticus, 
showing the basioccipital division, eo, and the basisphenoid division, es, of 
the median Eustachian canal, e. 
Fig. 10. A vertical section of the tympanic cavity of the Crocodilus biporcatus, show- 
ing bristles inserted into the basioccipital branch, eo, and basisphenoid 
branch, es, of the Eustachian tube ; c, the entry of the entocarotid canal. 
