56 LECTURE m. 



Trachelina. Glaucoma, Spirostomum, Trache- 



lius, Loxodcs, Chilodon, Phia- 

 li?ia, Bursaria, Nassula. 



KoLPODiNA. Kolpoda, Paramcecium, Amphi- 



leptus. 



OxYTRicHiNA. OxytricJia, Stylonychia, Uro- 



styla. 



EuPLOTTNA. Euplotes, Himantophorus, Chla- 



midodon. 



Order RHIZOPODA. 

 Shell, calcareous, camerated. 

 Locomotion, by branched, retractile processes. 



Tribe Monosomatia. 

 Family Amcebina. Genus Amceba. 



Family Arcellina. Genera Arcella, Difflugia, Gromia, Miliola, 



Euglypha, Trinema. 



Tribe Polysomatia. 

 Genera Vorticialis, Geoponus, Nonionina. 



Class ROTIFERA. (Wheel-animalcules). 

 Form, Body oblong, with a tail or post-abdomen more or less 

 jointed. Shell, when present, gelatinous. 



Locomotion, by peculiar aggregates of vibratile cilia on the head. 

 Digestion, by an alimentary sac or canal, in an abdominal cavity. 

 Circulation, by a pulsatile sac, vessels, and sinuses. 

 Respiration, by an aquigerous apparatus with peculiar vibratile 

 organs. 



Generation, oviparous or ovoviviparous. Sexes distinct. 

 Family Monotrocha. (Single-wheeled). Genera Pfygura, Iclitliy- 



dium, ChcBtonottis, G^cistes, ConocJiilus. 

 Family Schizotrocha. (Notch-wheeled). Genera Megalotrocha, 



Tubicolaria, Stephanoceros, Lacinularia, 

 Meliccrta, Floscularia. 

 Family Polytrocha. (Many-wheeled). Genera Entei-oplea, Hyda- 



tina, Notommata, Polyarthra, Triarthra, 

 EucJilanis, Salpina. 

 Family Zygotrocha, (Double-wheeled). Genera Rotifer, Acti- 



nurus, Noteiis, Philodina, Anuraa, 

 Brachiomis.* 



* In this summary adopted, with slight modification, from Siebold (XXIV.), 

 only those families and genera arc cited which best scr\'c as types of the organisation 

 of the respective grijups. 



