TABULAR SURVEY OF CHIEF CLASSES. 17 
METAZOA NON-CHORDATA 
Gasteropoda. Snails. 
Lamellibranchiata, Bivalves. 
‘Two smaller classes :—Scaphopoda and Solenogastres 
Cephalopoda. Cuttle-fishes. 
Mo ttusca. 
Insecta. ae 
Myriopoda. , Centipedes and millipedes. 
Prototracheata. Pertpatus. 
Crustacea. 
Palzostraca :—Trilobites, Eurypterids, and King-crabs. 
Some smaller classes. 
Arachnoidea. Spiders, scorpions, mites 
ARTHROPODA. 
Crinoidea. Feather-stars. (Cystoids and Blastoids, éxtinct.) 
Ophiuroidea. _ Brittle-stars. 
Asteroidea, Star-fishes. 
Echinoidea. Sea-urchins. 
Holothuroidea. Sea-cucumbers. 
EcHINODERMA. 
Annelids or 
Discophora. Leeches. Annulata. 
{ Chetopoda. Bristle worms. } 
Some smaller classes. 
( Brachiopoda. Lamp-shells. 
| Potyzc, e.g. Sea-mat (Flustra). 
Sipunculoidea, eg. Sipunculus. 
Worn: Nematoda. Thread-worms. 
Acanthocephala. 
Nemertea. Ribbon-worms. 
Rotifera. Wheel-animalcules. 
Cestoda. Tape-worms. 
{Brematoaa. Flukes. Platyhelminthes. 
\ (Turbellaria. Planarians. 
Ctenophora, ¢.g. Beroé. ‘ 
Actinozoa or Anthozoa. Sea-anemones. Alcyonarians and re- 
CGLENTERA. lated corals. 
Scyphomedusz or Acraspeda. Je 
Hydrozoa. Zoophytes and medisoids. 
PoRIFERA. Sponges. Calcareous and non-calcareous. 
PROTOZOA 
Inrusorta. Ruizopopa. SPporozoa. 
Simplest forms of animal life. 
