568 
Mr. De la Beche and My. Conybeare on 
concerning the place of the nostril in this animal ; the two openings 
generally to be traced in front of the orbits were at first thought to 
have discharged this function, but Sir Everard Home, having sub- 
sequently examined a specimen in which these apertures were exter- 
nally closed, was induced to retract this opinion ; and having ob- 
served that a passage supposed to form the nasal canal continued to 
the fore end of the snout, he indicated the propriety of looking for 
the nostril in that part, as in the crocodile. The examination of a 
specimen, in which the extremity of the snout is preserved in an 
entire and unaltered form, enables us to determine positively that 
the canal in question terminates in the narrow slit above described, 
and that there is no other opening whatever in this part. We still 
however feel great hesitation in considering this as the true nostril, 
since it is so minute as to be out of all proportion with the size of 
the animal, and we cannot feel quite satisfied that some forced and 
false position of the bones in the single skull alluded to may not 
have covered unnaturally the openings before the orbit, at first * 
supposed to be nostrils ; since in every other specimen we have ex- 
amined, amounting to nearly twenty, they appear to be well defined 
and perfectly open. 
The intermaxillary bones, <z, run much farther back than in 
the crocodile ; a variation partly arising from the prolonged form 
of the snout. Owing to their overlying the maxillary bones along the 
line of their junction, it is often difficult to distinguish them, especi- 
ally as they leave only a very small portion of the latter exposed on 
the outer side of the jaw ; they have also an overlying application 
against the nasal bones. These and the maxillary bones, b , £, fur- 
ther differ from those of the crocodile (in common with those of 
the lower jaw), by carrying the teeth in an open sulcus instead of 
separate alveoli. The maxillary bones are also more confined to 
