LIST OF THE CONTENTS 
OF EACH TANK. 
The Aquarium contains only marine animals and plants. 
All have been found in the bay of Naples. 
In the ensuing list only the most remarkable of the 
animals and plants are mentioned; the description given is 
purposely couched in colloquial language, being designed 
to convey, if possible, in a few w T ords a sufficient impres¬ 
sion of the animal to lead to its identification. The refe¬ 
rences in brackets give the page, where an account or figure 
of the animal will be found. The asterisk ( # ) before a name 
signifies that the occurrence of the animal is uncertain. 
The ascending streams of silvery bubbles in the tanks 
are the air drawn in by the sea-water, which is always 
being pumped in from dark tanks under the aquarium. 
Those animals and plants which are found near the upper 
part of a tank, will he seen double, owing to the reflec¬ 
tion against the surface of the water. All the tanks, hut 
especially, perhaps, Nos. 1, 3, 9, and 20, gain enormously 
by being seen in the sunlight between 12 and 2 o’clock. 
On the walls of most tanks will be seen the white 
tubes of Ciona (compare tank 4), the colonies of Botryllus 
p. 64) and other Compound Ascidians, and a little white 
Sponge (p. 12, fig. 1). These grow and breed in the water 
of the aquarium, attaching themselves to all suitable sur¬ 
faces. In most tanks are swarms of tiny, reddish-brown 
Opossum-shrimps (p. 46). — In comparing the Fishes with 
the figures in the Guide, it must he remembered that in 
many species the dorsal fin nearest the head is not visible ex¬ 
cept when erected (often for defence); notice, as an example, 
Labrax (p. 67) in tank 10. — The visitor must not rashly 
ascribe the power of walking about to Sponges, Tunicates, 
