322 



ZOOLOGY 



SECT. 



ORDER 3. PLOIMA. 



Kotifera in which locomotion is performed by the ciliated disc 

 only. The tail is usually forked and more or less retractile. 



Sub-order a. Illoricata. 



Ploi'ma in which the trunk is not covered by a lorica. 

 Including Hydatina, Polyarthra, Asplanchna, etc. 



Sub-order b. Loricata. 



Ploiima in which a lorica is present. 

 Including Brachionus, Euchlanis, etc. 



ce 



ORDER 4. SCIRTOPODA. 



Kotifera provided with setose appendages moved by striped 

 muscles : skipping movements are performed by the aid of these, 

 as well as swimming movements by the trochal disc. The tail is 



either absent or is repre- 

 sented by a pair of ciliated 

 processes. 



Including Pedalion and 

 Hexarthra. 

 br 



ORDER 5. 

 TROCHOSPH^ERIDA. 



Globular Kotifera having 

 the trochal disc represented 

 by an equatorial circlet of 

 cilia ; tail absent. 



Including Trochosphcera 

 only. 



ORDER 6. SEISONIDA. 



Marine parasitic Kotifers 

 (Fig. 273), with the trochal 

 disc reduced, the body long, 

 narrow, and ringed, with a 

 long slender neck-region, 

 and an elongated foot pro- 



FIQ. 273. Faraseison asplanchnus, female, . n , . 



x 230. a. genital aperture ; br. ganglion ; /. Vlded at its extremity With 



cv 



. . . . 



foot-glands ; m. mouth ; ma. mastax ; oe. oeso- 

 phagus ; ov. ovary ; st. stomach. (After Plate.) 



-run-frtraf or\ 

 P ei 



