CHAPTER XVI. 



PLATYHELMIA TURBELLARIA. 



PHYLUM PLATYHELMIA. 1 



CLASS I. TURBELLARIA. 



Order 1. Rhabdocoelida. 

 2. Tricladida. 

 3. Polycladida. 



CLASS II. TEMNOCEPHALOIDEA. 

 Order Dactylifera. 



CLASS III. TREMATODA. 



Order 1. Heterocotylea. 

 2. Aspidocotylea. 

 3. Malacocotylea. 



CLASS IV. CESTOIDEA. 



GRADE A. CESTOIDEA MONOZOA. 

 Order 1. Amphilinacea. 

 ,, 2. Gyrocotylacea. 

 ,, 3. Caryophyllacea. 



GRADE B. CESTOIDEA MEROZOA. 

 Branch a. DIBOTHRIDIATA. 

 Order 1. Pseudophyllidea. 



Branch 1). TETRABOTHRIDIATA. 

 Order 1. Tetraphyllidea. 

 2. Diphyllidea. 

 3. Tetrarhyncha. 

 4. Tetracotylea. 



APPENDICES TO PHYLUM. 



Rhombozoa, Orthonectida, Triclioplax, etc. 



1 Phylum Platylielmia, Lankester, 1890 (Platydmia, Vogt, 1851 ; Platodes, 

 Leuckart, 1854 ; Platydmintlies, Gegenbaur, 1859 ; Plat/ielminthes, Minot, 1877). 



