34 



was startled were wonderful ; it may be said to have constantly 

 blushed a most lovely purple. It was one of the most charming 

 sights I ever witnessed ; the change of colour in the Chameleon 

 was not to be compared to it. I hope Mr. Lloyd's acumen vrill 

 ultimately get over the difficulty of keeping this very interesting 

 species, which has the great advantage over the Octopus in swim- 

 ming about like a fish, by means of a membraneous expansion on 

 each side of the body taking the place of a fin. The small species, 

 Sepiola, has also lived for a short time in the aquarium. 



Some of the species of Cuttle-fishes attain a large size. One 

 was taken in the Atlantic which weighed two hundredweight. 



I do not think that it will be necessary to note in so short a 

 lecture any of the peculiarities of the shelled MoUusca, whether 

 bivalve or univalve, and shall therefore pass on to the next class. 



The well known Crabs, Lobsters, Prawns, and Shrimps, with 

 which the Aquarium is amply supplied, are included in the Class 

 Crustacea, which I shall now consider. 



We are all so accustomed to the sight of the common Crab, 

 that the strangeness of its form does not strike us. The name 

 Crab is derived from a Greek word, which signifies an animal 

 which walks on its head ; and it really looks as if the ten legs 

 were so attached, but this is only apparent, it is in no way real. 

 The Crab, in common with most of its allies, has the body formed 

 of 21 segments. 



Probably all I address know perfectly well that a Butterfly 

 commences life as a Caterpillar, hatched from an egg, changes 

 its skin four times in that state, then becomes a Chrysalis, and 

 ultimately a Butterfly. 



It is not, however, so well known to you all that the Crab 

 undergoes quite as remarkable a metamorphosis. 



The female Crab brings forth a very large number of eggs; 

 these each produce a minute creature, which is called a Zoea, and 

 is so imlike a Crab that so recently as the year 1835 the fact was 

 doubted by scientific men of eminence; however, by keeping 

 Crabs in aquaria, and watching their development from the egg, 

 the question has been long placed beyond the domain of con- 

 troversy. 



The Zoea is an active little creature, but of very small size ; 

 thousands have been produced in this aquarimn, but owing to 

 the impossibility almost, of suppling them with sufficiently small 

 atoms for food, they have all probably perished, though of this I 



