TABULAR SURVEY OF CHIEF CLASSES. 



METAZOA XOX-CHORDATA. 



MOLLUSCA. 



AKTHROPODA. 



/'Cephalopoda. Cuttle-fishes. 

 I Gasteropoda. Snails. 

 "| Lamellibranchiata. Bivalves. 

 l^Two smaller classes : Scaphopoda and Solenogastres. 



( Arachnoidea. Spiders, scorpions, mites. 



I Ir.secta. 



| Myriopoda. Centipedes and millipedes. 



< Prototracheata. Peripatus. 



I Crustacea. 



I Palaeostraca : Trilobites, Eurypterids, and King-crabs. 



VSome smaller classes. 



fCrinoidea. Fe; 

 I Ophiaroidea. 



IE! 

 IH. 



Chxtopoda. Bristle worms. . 



Discophora. Leeches. Annelids or 



Some smaller classes < Annulata. 



Feather-stars. (Cystoidb and Blastoids, extinct.) 



Brittle-stars. 



ECHINODEKMA. -| A.steroidea. Star-fishes. 

 Echinoidea. Sea-urchins. 

 Hololhuroitlea. Sea-cucumbers. 



"WORMS." 



/' Brachiopoda. Lamp-shell^. 



-J Polyzoa, e.g. Sea-mat (/''lustra). 



tSipunculoidea, c.g. Sipunculus. 



Nematoda. Thread-worms. 

 Acanthocephala. 

 Nemertea. Ribbon-worms. 

 Rotifera. Wheel-animalcules. 



I'Cestoda. Tape-worms. ~j 

 - Trematoda. Flukes. '-Platyhelminthes. 



V. vTurbellaria. Planarians. 



( Ctenophora, e.g. Beroc. 

 CuiENTEi - Scyphozoa. Jelly-fishes (Acraspeda) ; Actinozoa (Sea-anemones 



| and Alcyonarians). 



l.Hydroz< 



POKIFKKA. 



drozoa. Zoophytes and medusoids. 

 Sponges. Calcareous and non-calcareous. 



PROTOZOA. 



IXFUSORIA. RHIZOPOUA. SPOROZOA. 

 Simplest forms of animal life. 



