230 ] The Classification of Lower Organisms 



Family Cyclidina Ehrenberg op. cit. 244. Family Pleuronemidae Kent. Family 

 Pleuronemina Biitschli (1889). Similar, with a conspicuous undulating membrane 

 along one side. Cyclidium and many other genera. 



Family Urocentrina Claparede and Lachmann Etudes Inf. 1 : 134 ( 1858) . Family 

 Urocentridae Schouteden. Urocentrum, the single genus, top-shaped, with cilia con- 

 fined to two belts and a tail-like tuft, constantly whirling in the water. 



Family Trachelina Ehrenberg op. cit. 319. Family Tracheliidae Kent. Having an 

 anterior proboscis, the mouth at the base of this. Trachelius, Dileptus, Lionotus, 

 Loxodes, etc. 



Family Chlamydodontida [Chlamydodontidae] Glaus 1874. Family Chlamydo- 

 donta Stein, the mere plural of a generic name. Family Chilodontida Biitschli. Fam- 

 ily Nassulidae Schouteden. Flattened. The cytopharynx surrounded by longitudinal 

 rods, apparently of hardened protein, collectively forming a conical basket, enclosed 

 except when the cytostome is open for ingestion. Chilodon, Chlamydodon, Nassula. 

 c. Cytostome lacking; parasitic, mostly in invertebrates. Suborder Anoplophry- 

 INEA Poche; suborder Astomina Hall. 



Family Anoplophryida [Anoplophryidae] and seven other families, all named by 

 Cepede, 1910. 



Order 3. Heterotricha Stein Org. Inf. 2: 169 (1867). 



Suborder Spirotricka, sections Heterotricha and Oligotricha Biitschli in Bronn 



Kl. u. Ord. Thierreichs 1 : 1674 ( 1889). 

 Section Chonotricha Wallengren in Acta Univ. Lund 31, part 2, no. 7 : 48 ( 1895) . 

 Order Oligotricha Doflein Protozoen 240 (1901). 

 Orders Heterotrichaceae and Oligotrichaceae Hartog in Cambridge Nat. Hist. 



1: 137 (1909). 

 Orders Heterotrichida and Oligotrichida Calkins Biol. Prot. 386, 388 (1926). 

 Suborder Entodiniomorpha Reichenow in Doflein Lehrb. Prot. ed. 5, 3: 1195 

 (1929); Order Chonotricha Reichenow op. cit. 1211; suborder Ctenostomata 

 Kahl ex Reichenow op. cit. 1024. 

 Orders Spirotrichida and Chonotrichida Hall Protozoology 380, 411 (1953). 

 Infusoria having a sinistrorsc spiral band of cilia about the cytostome, these cilia 

 united (except in family Spirochonina) in triangular-attenuate membranellcs; not 

 having the body flattened and the cilia or cirri confined to the ventral surface. 



The peristomal apparatus of this order is an evidently derived character, so pecu- 

 liar as to appear to have evolved only once: in short, the order appears natural. There 

 are numerous subordinate groups. Several of these, of many species or of exceptional 

 character, have been segregated as additional orders; it is by an arbitrary decision 

 that they are here treated as suborders. 



a. Comparatively unspecialized examples. Suborder Spirotricha Biitschli. 

 Suborders Hctcrolrichina and Oligolrichina Flail. 

 Family Plagiotomina Biitschli op. cit. 1719 (1889). Family Plagiotomidae Poche 

 (1913). Peristomal area narrow and elongate, extending from the anterior end to a 

 cyto.^tome located near the middle of one side. Blepharisyna. Spirostomum. 



Family Bursarina Stein Org. Inf. 2: 169, 295 (1867). Family Bursariidae Kent. 

 Cytostome seated in a deep pit in one side of the body. Bursaria. Balantidium, para- 

 sitic in the gut of Amphibia and mammals; B. coli, a serious pathogen in man. 



Family Stentorina Stein op. cit. 169, 217. Family Stentoridae Claus. Peristomal 

 area anterior, more or less transverse. Stcntor, sessile and obconic, familiar. Follicu- 



