Dr. J. E. Gray on the Habits of the Pipe-fish, ^c. 495 



with the habits of the Pipe-fish, and induced to take a few notes. 

 There are three species now exhibited there. 



They swim with facihty, but not very rapidly, and they seem to 

 move chiefly by the action of the dorsal and pectoral fins. The former 

 is fully expanded when they move, and in very rapid motion, the action 

 being a kind of wave, commencing at the front end and continued 

 through its whole length, continually repeated, so as to form a kind 

 of screw propeller. The tail seems to be used rather as a foot than 

 as an organ of propulsion ; and the specimen that is furnished with a 

 rayed tail expands the rays when it uses this part, giving the end 

 of the tail the appearance of a webbed foot. 



They remain in a quiescent state in different positions, sometimes 

 horizontal, at others pendent, but generally more or less ascending 

 from the place on which the tail rests ; sometimes even nearly in a 

 perpendicular position, merely resting on the tip of the tail : at these 

 times the fins are generally at rest. 



I saw one specimen of the Serpent Pipe-fish with a simple acute 

 tail, which was resting in an erect perpendicular position with the tail 

 loosely curled round some shells of a Purpura that were attached to 

 the surface of the glass of the tank. 



This is an approach to the prehensile tail of the Hippocampi, but 

 still very different from the habit of that genus. 



Mr. Bartlett informs me that, whatever may be the colour of some 

 of the fishes, such as Flounders, Plaice, Soles, and Thombacks, when 

 placed in the tank, they soon modify their colours so as to be very 

 like that of the shell or sand which forms the ground of the tank ; 

 and as shells and shell-sand are now generally used to make the ground 

 of the tank, the fish become of a pale-brown, more or less mottled 

 colour. 



The flat fish, as Flounders, Plaice, and Soles, lie tranquilly at the 

 bottom of the tank, on the sand, with their eyes prominent, and their 

 mouth usually rather exserted and partly open ; but they swim with 

 facility, bending the side (or, rather, what in other fishes we should 

 call the dorsal and ventral edges) down, so as to raise the central line 

 of the body, and propel themselves with their tails. The pectoral 

 fins seem to be but little used, and they are often very rudimentary ; 

 the ventral fins, which are also small when present, are usually ex- 

 panded when the fish lies on the sand. 



It is much to be regretted that persons who have the leisure and 

 opportunity of observing these and other fishes in tanks do not give 

 us more particulars of their manners, and especially of the means by 

 which they propel themselves through the water, which is evidently 

 very different in the various faraihes and genera. The elongate, 

 cylindrical, subcompressed, or many-angled Syngnathus is generally 

 straight and stiff while moving from place to place ; while the elon- 

 gated rather compressed Blennies, as Gunnelliis and Zoarces, pro- 

 pel themselves forward with a horizontal serpentine motion, appa- 

 rently keeping their bodies erect by the dorsal fin and the expanded 

 pectorals. 



There is one circumstance connected with the fishes in these tanks 



