204 



The gills, I think, have a double action. When the mouth is 

 shut and the gills expand, water will then rush in to fill up the 

 vacuum and carry any food retained on the inside of the cullen- 

 der apparatus towards the centre of the mouth over the tongue, 

 where there are two temporal hloic-holes^ the valves in which 

 will now open and allow the water to escape upwards, while the 

 tongue holds the food and delivers it into the gullet. These 

 temporal hloic -holes, I conceive, act like safety or escape valves; 

 thus causing the cullender apparatus, by a suction' through the 

 gill-openings, to discharge the contents they have retained from 

 a previous mouthful, into the centre of the mouth, and bringing 

 the food opposite the throat into a position where it can be most 

 easily swallowed. 



When the head was being hoisted ont of the schooner, and 

 suspended by a tackle hooked through the under jaw, the gap 

 looked fearfully large, and presented a space so capacious, that a 

 gentleman who was present stepped between the jaws and stood 

 nearly upright with his hat on. The teeth are small for the size 

 of the animal ; are placed in rows generally six and seven deep. 

 They are shaped like a cone flattened on one side, and curved 

 upwards. The cartilaginous bones of the jaws exhibit a mem- 

 branous structure, the sheets or fibres passing transversely under 

 each other in each alternate layer. 



On making a longitudinal slit through the centre of the snout, 

 I found that the knife passed into a large cavity, or chamber, 

 filled with the gelatinous matter that was seen to ooze through 

 the exterior pores. This gelatinous matter had the appearance 

 of a solution of starch, and seemed to be attached to soft fila- 

 ments which proceeded from secreting vessels. I could not dis- 

 cover any connection between this chamber and the olfactory 

 apparatus. 



The Cranium is very small, and in fact looks rather like an 

 enlargement of the end of the spinal column. The bone seems 

 to consist of a single piece, and to be placed well back in the 

 head, so that the optic nerve must be of great length when we 

 consider the situation of the eye. The auditory apparatus escaped 

 my observation. 



The Caudal Jin vertical, the extremity of a crescent shape, the 

 extremes being eight feet apart. From the medial line to the 



