284 POPULAU HISTORY OF THE AQUARIUM. 



generally lives as much out of sight as possible, under 

 shelter in dark corners, but darting out occasionally, rarely 

 rising to the surface, except for the purpose of seeking 

 prey. It is very remarkable for the changes that constantly 

 take place in its colours, like those of a Chameleon, but 

 more decided. Sometimes, it is of a general blackish hue, 

 clouded with darker patches. Sometimes, it is pale brown 

 with dark and white spots. Possibly this is connected with 

 the animal's ''feelings^' for he is observed to become dark- 

 est when most excited ; and, when devouring a victim, 

 lours over him ^^ black as night." 



The ventral fins of this fish are united so as to form an 

 oval sucking disc. It enables the fish to seize and retain 

 a hold on surfaces which he is not inclined to relinquish for 

 the moment. He adheres, by means of this sucker, to 

 pieces of rock and sides of the tank. I think he uses it 

 partly in crawling, as he sometimes is observed to do, over 

 perpendicular and diagonal surfaces. 



MUGIL CHELO. 



The habits of the Grey Mullet are the reverse of the 

 preceding, for, while the latter generally remain quietly 

 near the bottom of the tank, the former afiects the surface, 



