
MARINE AQUARIA 

find a place in this book. Only the most common /iftora/ forms, those 
living on or near the shore, are mentioned and those of greatest interest 
to the collector are described. [The Marine fauna may be roughly classed 
as? — 
I. Porifera. Sponges. 
Polyps, etc., Seaweedlike Zodphytes and small Jellyfishes, some 
| of the Corallines, and Hydrozoa generally. 
I]. Coelenterata. 4 Larger Jellyfishes and Scyphozoa generally. 
| Sea-anemones, Actinoid corals and Actinozoa generally. 
Comb-jellies and Ctenophora generally. 
III. Vermes. Worms and Leeches. 
IV. Molluscoida. Sea-mats or Polyzoa, and Corallines or Brachiopods. 
Se ee ee ( Starfishes, Brittle-stars, Sea-urchins, Sea-cucumbers, Feather- 
: ‘ (stars, Sea-lilies and Radiates generally. 
( Crustaceans, Entomostraca, Barnacles, Lobsters, Shrimps, etc., 
' 
VI. Arthropoda. { King Crabs, Sea Spiders, Squilla, and the Amphipods and Iso- 
| pods in general. 
( Limpets, Tops, Whelks, Periwinkles and other Gasteropods ; 
VII. Mollusca. 4 Mussels, Clams, Scallops and Pelecypods generally. 
| Cuttles and other Cephalopods. 
VIII. Chordata. Sea Squirts and allied forms. 
EX, Pisces: Fishes. 
PoriFERA OR Sponces. These constitute one of the lowest forms 
of animal life, propagating by gemmation or budding. The sponge of 
commerce is the skeleton or framework, the organic portion being a soft 
and jellylike substance of which the external layer is composed of flat cells 
with numerous pores and larger openings for inhaling and straining the 
water; the middle layer of cells having various functions, as the formation 
of the framework, digestion and reproduction; and the internal layer of 
cylindrical cells leading to sacs, each having a flagellate hair to create a 
current.) Uhese take im the food, ‘digest 1t and eject the excrement: 
Almost every seaweed, rock, mollusc and crab has some member of this 
family attached to it, which vary in size from tiny specks to large and sub- 
stantial masses of varying forms and colors. Sponges are roughly divided 
into two classes, Calcarea and Non-Calcarea. 
The genera most usually met with are the following, of which a brief 
description will suffice, as they do not survive in the marine aquarium. 
Duserpe1a, having an imperfectly cellular body composed of a gela- 
tinous membrane covered with amorphous particles of sand. 
GranmiA, having a firm, elastic body with calcareous spicula com- 
pacted in a gelatinous base. 
EIS) 
