296 Animal Biology 



Embryo 



Pharynx 



Fntesfcinc 



Cuticle 



.Moath 



Uterus 



Fig. 98. — "Vinegar eel" {Turbatrix [Anguillula] oceti) of the class Nernatoda, 



phylum Nemathelniinthes (much enlarged). 



Ijophacjus Ovary qenitalpore 



Mouth Nerve rincj 



Mouth 



Tema]Q 

 Te5t\3 TrttQstine Somha) vesicle Ar)us Bursa 



Male 



Fig. 99.^ — American hookworm {Necator americanus) , adults, of the phylum, 

 Nemathelniinthes. The actual length of the female is 10 mm., and of the male, 

 7 mm. 



A 



Muscle fibres 



Cyst for 

 protection 



Muscle fibre? 



Orqans of attachmeryt 



C 



\rtesbne j^'^.^ 



Ferf orated cell bodies of intestine Pharynx 



/^erve rmq 



\' \ 



Fig. 100. — Trichina or "pork worm" (Trichinella spiralis) of the phylum 

 Nemathelniinthes. A, Trichina between muscle fibers; B, trichina between muscle 

 fibers and surrounded by a cyst; C, trichina (male); D, trichina (female). 



