The Zoologist — October, 1873, 3703 



naturalists had successfully had recourse to this plan ; but we believe the 

 merit of first having perfectly succeeded with an arrangement of the kind in 

 London is due to Mr. Warington. By arranging sea-plants and animals 

 in a limited quantity of sea-water, he so maintained the balance of animal 

 and vegetable life that for several months they required neither fresh water 

 nor any mechanical aeration. It is the adoption of this plan on a large 

 scale that constitutes the novelty of the Vivarium now opened to the public 

 in the Zoological Gardens. At the present moment there are in the glass 

 house six large tanks of glass containing marine invertebrate animals and 

 fish. These tanks have been arranged in something like zoological order. 

 The first contains a variety of crustaceans, crabs, lobsters and shrimps. 

 Here may be seen in living activity species of these creatures only to be 

 caught by the dredge, and which have been only occasionally seen when 

 cast up on our coasts or pinned down in our museums ; several of the 

 spider crabs — which are inhabitants of the deep sea — will attract more 

 attention among these specimens. In the second tank is a collection of 

 Echinodermata. A third tank contains a collection of sea anemones or 

 animal flowers. The more common forms of these lowest members of the 

 great family of polypes are scarcely unknown to the least curious visitors 

 of our sea-coasts, but it has fallen to the lot of few to see them to such 

 advantage as they now may here. In variety of colour they almost vie 

 with a bed of tulips, and they will enable the observer to understand some- 

 thing of the beauty which arrests the attention of the traveller in the 

 South Seas, where these creatures and their allied forms abound. The 

 naturalist will also find in this tank some of the less common of the species 

 of the family Actiniadse which are found on the British coasts. In a fourth 

 tank is a collection of the British MoUusca. Those who gather shells by 

 the sea-shore will recognise many of their old acquaintances in this depart- 

 ment, but no longer as uninhabited dwellings. Each contains its proper 

 tenant. Several species of ascidian MoUusca are found here, whose rough 

 membranaceous and ungainly exterior would hardly lead to the conclusion 

 that they are allied to shell-fish at all, did not their interior inhabitant 

 reveal the fact. In another tank a highly interesting group of MoUusca, 

 the nudibranchiate, are to be seen. These have no shells, and are remarkable 

 for their delicate colouring, and for the curious forms assumed by their 

 gills or breathing organs, which being placed outside of their bodies have 

 got for them the name of naked-gilled. The species of this family belong 

 to the genera Doris and Eolis. In the fourth tank are also contained some 

 species of barnacles and sea-acorns (Cirripedia), which, with their hard 

 moUuscous-Hke shells, were once included under the MoUusca, but are 

 now known to have an internal structure which allies them with the articu- 

 lated tribes of animals : in this tank are some small species of sea-fish, 

 including the blenny, the fifteeu-spiued stickleback, the wrasse and the 



