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1. The Sea-lilies (Crinoidea), 2. the Starfish (Asteroidea), 

 3. the Sea-urchins (Eehinoidea),4. the Sea-cucumbers (Holo- 

 thuroidea). 



Of the first class the Aquarium possesses the Comatula 

 mediterranea, a very beautiful creature, which varies much 

 in colour. Straw-coloured, orange, blood-red and brown-and- 

 white examples may often be seen in great quantities in the 

 tanks. They generally adhere to corals or annelids, so that 

 they look almost like gay flowers springing up in various places. 



The Aquarium has a great number of Starfish. There are 

 the Asteracanthion, Astropecten, Luidia, etc. Some of 

 these creatures, for example the Ophidiaster, are found on 

 close inspection to be very beautiful, being not only brilliant 

 in colour, but having beautifully marked skins. 



The Brittle- starfish or Ophiuridea are numerously repre- 

 sented; but they do not so much attract the attention of the un- 

 learned: Ophioderma longicauda, etc. 



The Sea-urchins, on the contrary, are very striking. Above 

 all the Echinus melo is remarkable for its light flesh tint, 

 and size. The Echinus liyidus and kindred are eaten, that 

 is, the shell is opened and the bright yellow ovaries are taken 

 out and eaten like oysters. The Toxopneustes brevispinus 

 is of a very beautiful violet-brown colour, and the Dorocida- 

 ris hystrix is distinguished by its few but large and strong 

 spines. 



Sea-cucumbers are numerous in the gulf of Naples, and the 

 Aquarium can show more than six different species, some in 

 great quantities, especially the large Holothuria tubulosa, 

 an immense Sea-cucumber of a brown colour, more than a foot 

 long. Another remarkable Holothuria is the H. regalis, the 

 body of which is not round, but square and flat. These Holo- 

 thuridae are remarkable for a circumstance to which we will 

 now draw your attention. In the body of these creatures is 

 often found alive a beautiful I little fish, about 20 centimeters 

 long, the Fierasfer acus, which sometimes protrudes its head 

 from the anus of its host. It lives on small crabs, to catch 

 which it must leave its curious quarters. 



Certain Holothuridae are eaten, especially by the Chinese; 

 the so-called Trepang is the body of the Holothuria edulis 

 emptied of the intestines and dried in the sun or by artificial 

 heat. Thousands of Malays and Chinese are occupied in fishing 

 and drying this food, which European palates find can only be 

 eaten when strongly spiced. Whole fleets of boats sail annually 



