58 GUIDE TO THE FOSSIL INVEETEBJRATE ANIMALS. 



Gallery We pass now to Gallery VIII, which contains fossils 

 belonging to several of the great divisions of the animal 

 kingdom. These are arranged in the following order, 

 beginning on the right of the entrance and continning down 

 the east side of the Gallery, and then crossing to the west 

 side : Echinoderma, Annelida, Arthropoda, Brachiopoda, 

 Bryozoa, and Mollusca (except Cephalopoda). These groups 

 will now be taken in that order. 



ECHINODERMA. 



East Side. The Sea-Urchin, the Starfish, the Brittle-Star, the Feather- 

 Star, and the Sea- Cucumber, all of which live in modern 

 seas, are examples of this subkingdom. Though differing 

 from one another in outward appearance, they resemble one 

 another and differ from the rest of the animal kingdom in a 

 number of characters which are briefly stated in a label on 

 the wall near the entrance. For further information as to 

 the anatomy and general appearance of forms now living the 

 visitor should consult the Starfish Gallery of the Zoological 

 Department and the Guide relating thereto. 



The examples mentioned above represent each one of the 

 Classes into which this subkingdom is generally divided. 

 Taking them in the same order, these are Echinoidea, 

 Asteroidea, Ophiuroidea, Crinoidea, and Holothurioidea. 

 Remains of all these are found as fossils, and there are also 

 at least three Classes, now extinct, and only known from 

 fossils in Palaeozoic rocks. They are called Cystidea, 

 Edrioasteroidea, and Blastoidea. 



Class CRINOIDEA. 



Table-eases This Class comes first in the present arrangement of the 

 Wall eases ^^-'■-^^^y- Specimens of some Eecent species are placed in 

 18, 17, 16. the Wall-case close to the entrance, and their flower-like 

 appearance enables one to understand why these beautiful 

 animals should be called by this Greek word, meaning 

 Lily-shaped, and by the popular name Sea-lilies. Though 

 they bear this name, and though many of them have a long 

 stalk and may be fixed to the sea-floor, still they have 

 nothing whatever to do with plants, but are highly organised 

 animals, with a distinct digestive system shut off from the 

 main-body cavity, with nerves, with blood-vessels, and with 



