PL A TYHELMINTHES 



NEMA THELMIN THES 



■MOUTH 



P/tOBOSC/S 



COELOti 



INTESTINE 



BODY WALL 



REPHODUCTIYE 

 DUCT 



FIG. 40. HEklErtTINEA-CEREBRAIVLUS 

 TRQCMELMttrniES 



FIG. 41 ASCARIS 

 MOLLUSX^fDEA 



CIRCLET 

 OF CILIA -^■ 



MOUTfT 



MAST AX 



FOOT 



FIG. 42. ROTIFER 



FIG. 43. BRrOZOA-A PORTION 

 OF BUGULA 

 Fig. 40. — ^Nemertinea are frequently included in the phylum Platyhelminthes. All 



are free living marine animals, some varieties attaining a length of many feet. 



Fig. 41. — Ascaris, a common representative of the phylum Nemathelminthes. 

 This form and its relatives inhabit the intestines of vertebrates. Other members 

 of the phylum are parasitic in many plants and animals; many representatives are 

 free living. In the figure a portion of the body has been diagrammed to show 

 the structure. 



Fig. 42. — A rotifer, representative of the phylum Trochelminthes, much enlarged. 

 TTiese animals may be found attached by the foot and feeding, or swimming 

 about in the water. (Re-drawn after Van Cleave: Invertebrate Zoology, published 

 by the McGraw-Hill Book Co.) 



Fig. 43. — Bryozoa, a representative of one type of the phylum Molluscoidea. Plume- 

 like forms of this type occur in fresh water. 



