APPENDIX 183 



Order 1. ANTHOZOA. Solitary or colonial polypoid scypho- 

 zoans without medusoid generation ; a calcareous skeleton present 

 in many : corals and sea anemones. 



Suborder 1. Octocoralla. Anthozoans with eight mesenterial 

 ridges and eight branched tentacles. Ex. Corallium. 



Suborder 2. Hexacoralla. Anthozoans the number of whose 

 mesenterial ridges and tentacles is six or some multiple of six ; 

 tentacles unbranched. Ex. Metridium. 



Order 2. SYPHOMEDUS^E. Scyphozoans with large opaque 

 jelly-fishes and minute hydroid polyps. Ex. Aurelia. 



Class III. Ctenophora. Cnidarians with eight bands of ciliated 

 ridges on outer surface. Ex. Mnemiopsis. 



Division II. METAGASTROZOA(COELOMATA). Bilaterally sym- 

 metrical animals (although in some cases the adult is secondarily 

 radiate) with body -cavity (ccelom) and specialized digestive canal ; 

 all the higher animals, which develop beyond the condition of the 

 gastrula. 



Type III. TKOCHOZOA. Metagastrozoans whose common 

 descent and relationship are shown by their possession in some 

 form of a trochophore larva or of an embryonic form allied to it. 



Subtype I. VEBMKS. Trochozoans which become adult while 

 still in the trochophore stage or (the Platyhelminthes) in the stage 

 immediately preceding it (protrochula stage). Worm-like, often 

 parasitic animals ; usually unsegmented, and without distinct 

 head. 



Class I. Platyhelminthes. Flatworms ; no anus present ; body- 

 cavity filled with a connective tissue called parenchyma. 



Order 1. TURBELLARIA. Small free-living flatworms, with 

 ciliated outer surface and median mouth. Ex. Planaria. 



Order 2. THEM AT OD A. Small parasitic flatworms, without 

 ciliated outer surface, and with anterior mouth ; flukes. Ex. 

 Distoma. 



Order 3. CESTODA. Elongated, tape-like parasitic flatworms 

 with segmented, unciliated bodies ; no digestive system ; tape- 

 worms. Ex. Taenia. 



Class II. Nemathelminthes. Round thread-like worms ; usually 

 parasitic. Ex. Ascaris. 



