210 AUGUST. 



except sufficient to form the permanent dorsal. This 

 fin, in the whole family, is excessively filmy, and is, 

 during the action of swimming, fluttered with a very 

 rapid screw- like vibration. 



Slight as are the organs of motion, they are sufficient 

 for the Pipe-fish's ordinary exigencies ; and Mr. Patterson 

 has recorded an interesting example of their capability 

 to achieve movements of an unusual kind. He had 

 captured the finest of our species, 1 which he had com- 

 mitted to a basin of sea- water. " One of the long-bodied 

 Crustacea, which are abundant during fine weather, and 

 had been captured at the same time, was placed in the 

 same vessel. It was a species of Gammarus, and about 

 an inch in length. The Gammarus would seem to have 

 got tired of swimming, and, for a resting-place, it fixed 

 itself on the back of the Pipe-fish, close to the tail. The 

 fish had not been a consenting party to this arrange- 

 ment, and soon evinced its dissatisfaction, by lashing 

 the tail with great violence on each side, to dislodge 

 the intruder. He, however, kept his hold ; and so soon 

 as the fish ceased for a few seconds, he crept a little 

 further up on the back, as if aware that the velocity of 

 movement was less near the centre of the circle. The 

 fish lashed the water again with great violence, but 

 without any good result ; and so soon as it stopped, the 



1 Syngnathus acus. 



