94 



SEA LAMPREY. 



in front are fixed in a single bone, which is suspended from 

 the skull; to which also the pair above the gullet are affixed. 

 This bone forms a ring; but the rows above, or on the roof, 

 stand, each tooth singly, on a bed of tendinous substance. 



Referring to what has been already said of the bones of the 

 head, it should be added that the brain is small and not 

 covered by them; and even the passage from the top of the 

 head through an organized chamber to the gills is behind 

 them; so that more probably they answer to the nasal and 

 lachrymal bones of the higher animals, as appears to be Dr. 

 Grant's opinion in his Lectures. The animal senses of this 

 tish appear to be acute. 



Moutli of Sea Lamprey seen from above— to shew the crown of teeth, or 

 tooth on the place of a tongue. 



