80 
Tanks No. 21 and 22. 
sharp bent teeth which causes the wounds to heal so slowly. In the 
Aquarium they can be kept for years. Recently it has been proved that 
their blood acts as a violent poison (as does 
that of the Common Eel) when injected into 
the blood of a mammal. 
A quite unique appearance amongst 
fishes is afforded by the Sea-horse and its 
allies, which are collectively classified as 
Lophobranchii or "tuft-gilled” fishes, on account 
of the form of their gills. Every one will 
know the Sea-horse, Hippocampus (Fig. 
138), which is sold dried, as its hard skin 
Fig. 137. Muraena helena, ^4 nat. size. Tank 11. 
preserves the shape of the animal. The life and 
habits of these fish, so common in the Bay 
of Naples, are very attractive. Everything about 
them seems as different from other fish, as 
is their shape, which reminds one of a grace¬ 
fully carved chess figure. They seem to do 
best in tanks No. 21 and 22, where plants or 
worm-tubes give them plenty of opportunity 
of fastening themselves with their finless tail. 
Here their small mobile eyes are constantly 
looking for the small animals which may be 
attached to the tubes. When swimming in their 
graceful manner, their dorsal fin is in constant 
wave-like motion. They float up and down, 
bend themselves about, chase each other, or 
swim in couples clasping each other with their 
tails, or in other laughable attitudes. This playfulness is chiefly exhibited 
in autumn, which is their breeding season; and loving couples may be 
Fig. 138. Hippocampus 
guttulatus, ^2 nat. size. 
Tanks 21 and 22. 
