118 WORMS. 



CLASS V. VERMES. WORMS. 



ORDER I. INTESTINA. 



Naked simple animals, without limbs. 

 A. Found within other animals : without eyes, 



1. Ascaris. B o dy round elastic, tapering towards each 



end : head with 3 vesicles : intestines pellucid, white* 

 spiral. 



2. Trichocephalus. Body round, elasic, variously 



twisted, much thicker in front and furnished with a 

 slender protrusive proboscis : tail long, capillary, 

 tapering to a fine point. 



3. Filaria. Body round, filiform, of equal thickness, 



quite smooth : mouth dilated, with a roundish concave 



ii P . 



4. Echinorinchus. Body round : movtfi with a cylin- 



drical retractile proboscis, crowned with hooked 

 prickles. 



5. Facioi^a. Body flatfish, witfe an aperture or pore 



at the head* and generally another at a distance 

 beneath. 



6. Taenia. Body flat, composed of numerous joints: 



head with 4 orifices ? for suction a little below the 

 mouth : mouth terminal, generally crowned with a 

 double series of retractile books. 



B. N&t inhabiting the bodies of other animals. 

 a. Furnished with a later al pore. 



% Lumbrictjs. Body round, annulate, with generally a 

 fleshy belt near the head, mostly rough with minute 

 concealed prickles placed longitudinally. 



S. SiPimcujLUS. Body round, elongated : mouth cylindri- 

 cal, terminal, narrower than the body: aperture at 

 the side of the body, wart-like. 



9. Planaria. Body flattish, pointed behind, gelatinous, 



with a double ventral pore, proceeding with a slow 

 and uniform motion : mouth terminal. 



10. Hirudo. Body oblong, truncate at each end, cartila- 

 ginous, unarmed, moving by dilating the head and 

 tail and contracting itself into an arch. 



b. Without the lateral pore. 



11. Lineus. Body a little depressed, linear, smooth: 

 mouth longitudinal, placed underneath. 



12. Gordius. Body round, filiform, of equal thickness, 

 smooth. 



