British Reptiles and Amphibians 



6. PLATYHELMINTHES (Gr., platys, flat ; helmins, 

 -inthos, a worm). Flat- Worms, Whirl- Worms, Liver- 

 Flukes, Tape- Worms, Ribbon- Worms. 



7. NEMATODA (Gr. nema, a thread ; eidos^ form). 

 Thread- Worms (unsegmented). 



8. POLYZOA (Gr. polys y many ; zoon, an animal). 

 Sea-Mats, etc. The exact position of the Polyzoa in 

 the Animal Kingdom is not determined. It is suggested 

 that they should be joined with the Brachiopods to form 

 a phylum under the name a Molluscoidea." 



9. ROTIFERA (L., rota, a wheel ; ferre, to carry). 

 This phylum comprises the so-called " Wheel- 

 Animalcules," or Rotifers. They are minute in pro- 

 portions, requiring microscopic examination, yet they 

 are well-organized animals. 



10. MOLL USCA (L., mollis^ soft). Snails and so-called 

 " Shellfish," Cuttle-Fish, Slugs. 



11. ARTHROPODA (Gr. arthros^ a joint ; pous, a foot). 

 Animals with jointed appendages or limbs. This phylum 

 includes the Crustacea (Crabs, Lobsters, Barnacles, 

 Water-Fleas, etc.), the Centipedes, insects, Spiders, and 

 Mites. 



12. CHORDATA (Gr., chorde, string), including all the 

 vertebrate animals. 



The phylum Chordata, or, as it is sometimes 

 termed, " Vertebrata," may be divided into two 

 subphyla : 



i. ACRANIA (Gr., <?-, without ; cranion, skull), 

 including animals such as Lancelets and Ascidians, 



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