ITS HABITS. 171 



vessel, or to the prominent knobs of the stones by their 

 sucker, and here they remain for an indefinite time, 

 sometimes for hours, at others only a few seconds, 

 throwing their beautiful eyes about in insatiable curio- 

 sity, fanning the water with their transparent pectorals, 

 or whisking the painted tail about. Now and then 

 they make a sudden snap, doubtless at some passing 

 animalcule, with an audible sound, and the emergence 

 of a bubble of air from the top of the water, whence the 

 muzzle is frequently projected. They have an awkward 

 habit of throwing themselves out of a shallow vessel ; 

 and if you are not on your guard you may find your 

 little pets dead and dry on the carpet. They are 

 inquisitive little things; if a new stone or shell or 

 tuft of serpulse is put into their vessel they soon dis- 

 cover it, and may be seen exploring it in every part ; 

 and it is amusing, when you are examining them with a 

 lens, to note how thoroughly mutual is the investigation ; 

 for you can see by the direction and motion of the eyes 

 that the little fish is watching you as interestedly as 

 you are observing him. 



I do not think that the adhesion of the ventral sucker 

 is effected exactly as has been supposed, by a vacuum 

 produced in the area of the united ventral fins ; but by 

 the combined action of some minute fleshy sucking 

 disks, which are arranged in two groups, in front of 



