48 



They were remarkable, he said, as still preserving certain em- 

 bryological characters. The most conspicuous of these vvas the 

 prolongation of the vertebral column in the form of a fleshy 

 filament, distinct from the caudal fin, which had at times a vibrat- 

 ing motion, involuntary, and quite distinct from the motions of 

 the tail itself, as is seen in some embryos. This singular formation 

 shows that the caudal fin is properly an appendage to the lower 

 surface of the dorsal column, a true second anal, and not the 

 proper termination of the column. The specimens exhibited 

 showed their affinity to reptiles, by their motions and attitudes ; 

 the spine being more flexible than in ordinary fishes, and their 

 position, when at rest, being frequently more or less bent, par- 

 ticularly towards the tail ; peculiarities arising from the ball and 

 socket joints of the vertebrae, — a proper reptilian arrangement. 

 The manner of feeding also is unlike that of fishes, and resem- 

 bles that of reptiles. Other fishes take their food with open 

 mouth, and swallow it at once ; but this one approaches its prey 

 slyly, sidewise, and suddenly seizing it holds it in its jaws, until, 

 by a series of movements, it succeeds in getting it into a proper 

 position for swallowing, as is the habit with alligators and lizards. 

 The ball of food in the body of this fish is seen to move gradu- 

 ally, as it distends the body in its progress, from one end to the 

 other, as is seen in snakes. This fish is also remarkable for the 

 large quantity of air which escapes from its mouth. The source 

 of this Prof. Agassiz had not been able satisfactorily to determine. 

 At certain times it approaches the surface of the water, and 

 seems to take in air, but he could not think that so large a 

 quantity as is seen adhering in the form of bubbles to the sides 

 of the gills could have been swallowed, nor could he suppose 

 that it could be secreted from the gills themselves. These differ- 

 ent interesting facts were noticeable in the specimens exhibited, 

 which were fed for the occasion on live minnows, the only food 

 they could be persuaded to take. 



Dr. A. A. Hayes read by its title the following paper — 



ON THE STATE IN WHICH PHOSPHATE OF LIME EXISTS IN 

 SEA-WATER. 



In a description given to the Society of a consolidated phos- 

 phate of lime, arising from the action of atmospheric agents on 



