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out of the very net. In the Aquarium they are very lively , 

 and fond of swimming in company. 



Compared to the glittering breams, the Sea-raven (Corvina 

 nigra) is remarkable for its dark brown colour. It is a peace- 

 able fish , always keeping close to its fellows , and r head 

 downwards , seems to be thoughtfully examining the bottom 

 of the tank. 



Of the PlectognatMj so rich in strange forms of a tropical char- 

 acter], which may be known to the visitor in the globe-fish 

 seen in Museums of Natural History, we are acquainted with 

 only two species that inhabit the Gulf of Naples : the moon- 

 fish or swimming -head (Orthagroriscus mola), and the fca- 

 lista (Balistes capriscus). The first is, till now, one of the 

 greatest rarities in the Aquarium , and scarcely ever outlived 

 its imprisonment more than a few days, so that we can report 

 nothing interesting as to its habits. We have become much 

 better acquainted with the Balista, of which we have always 

 specimens from spring to autumn. This fish is full of interest. 

 Its very shape, its one sided and out of all proportion short 

 and thick body, at once excites attention, and its brilliant blue 

 eyes, as well as its narrow pointed mouth armed with a few 

 closely-set incisors, heighten the singularity of its appearance. 

 It is a lively, curious, sociable fish, which, however, only fully 

 shows its nature during the summer months , for it is very 

 sensitive to cold, and regularly sinks to the bottom of the tank 

 when winter commences. It lives on shell-fish and crabs, which 

 it breaks with its powerful teeth, making such a noise in doing 

 so that it can be heard through the glass of the tank. It snatch- 

 es food from the very jaws of the large tortoises that share 

 its tank , and attacks the eyes of lobsters and craw-fish , so 

 that these animals cannot be kept in the same tank. 



The Balistae have given us a few remarkable proofs of their 

 power of discrimination, which may be briefly related here. One 

 day a dying shark (Carcharias glaucus) , about five feet 

 long, was put into the large tank containing the Balistae, where 

 he died a few minutes after. Scarcely did the Balistae catch 

 sight of the animal when they fled in mad fright, and hid in 

 the darkest holes and crevices cf the rock- work, whence they 

 cast shy glances, changing their colour the while, on the dying 

 monster. They had recognised their deadly enemy at a glance, 

 and showed their terror in for fishes an extraordinary manner. 

 Another case was that of a single Balista which the keeper had 

 repeatedly tried to catch , in vain. Each time it slipped into 



