348 Ciliophora 



Kahl (100), Placus Cohn (158; Fig. 7. 6, D), Plagiocampa Schewiakoff (100; Fig. 7. 6, 

 E, F), Platophrya Kahl (100; Fig. 7. 6, B), Prorodon Ehrbg. (100, 165, 210; Fig. 7. 6, A, 

 N), Pseudoprorodon Blochmann (100; Fig. 7. 7, F), Rhopalophrya Kahl (100), Spasmo- 

 stoma Kahl (98; Fig. 7. 6, M), Stephcniopogon Entz (100), Trachelocerca Ehrbg. (13, 

 100, 188; Fig. 7. 6, K. L), Trachelophyllum Claparede and Lachmann (100, 165), Uro- 

 tricha Claparede and Lachmann (100, 165, 188; Fig. 7. 7, A). 



Family 10. Loxodidae. As in the Amphileptidae, the body is compressed 

 laterally but the "ventral" margin, on which the cytostome lies, tends to 

 be slightly concave. 1 he right surface is ciliated, the left naked. The 

 presence of Midler's bodies (Fig. 1. 16, D; 7. 7, J) is characteristic. Algae 

 and bacteria are the usual food. 



Two genera are recognized: Loxodes Ehrbg. (102, 165; Fig. 7. 7, J), which includes 

 fresh-water species; and Remanella Kahl (102; Fig. 7. 7, E), which includes only marine 

 ciliates. 



Family 11. Metacystidae. This family (97) is characterized by a terminal 

 cytostome and a firm cortical layer enclosing a peculiar alveolar zone. The 

 cytostome may be rounded or slit-like, and in certain species, opens into 

 an endoplasmic cavity ("receptacle"). These ciliates apparently feed 

 mainly on bacteria. A pseudochitinous lorica is characteristic, although 

 a gelatinous lorica has been reported in rare cases. 



The family includes only three genera: Metacystis Cohn (100, 165; Fig. 7. 8, H), 

 Pelatractus Kahl (100; Fig. 7. 8, I, J), and Vasicola Tatem (100, 165; Fig. 7. 8, K). 



Family 12. Nassiilidae. In this hypostomatous family the body is com- 

 pletely ciliated, although the dorsal ciliation is less dense than that of the 

 ventral surface. A pharyngeal basket is typical but there is no ventral 

 stylus like that of the Dysteriidae. The family contains marine and fresh- 

 water ciliates which feed mainly on diatoms and other algae. 



The following genera are included: Chilodontopsis Blochmann (102; Fig. 7. 8, B), 

 Cyclogramma Perty (102), Eucainptocera da Cunha (102), Nas.sula Ehrbg. (102, 165; 

 Fig. 7. 8, C-E), Orthodon Gruber (102; Fig. 7. 8, A), and Paranassula Kahl (102; Fig. 

 7. 8, F, G). 



Family 13. Pycnothricidae. These ciliates occur in the cecum and large 

 intestine of various mammals. Species of Collinella and Pycnothrix are 

 known from Procavia (Hyrax); Biixtonella, from cattle; Nicollella, and 

 also Collinella, from Cteiiodactylus. The body is completely ciliated and 

 a long groove usually leads to the cytostome, which may lie near the 

 middle or at the posterior end of the body. In Pycnothrix monocystoides 

 (which reaches a length of 2-3 mm), there is no single cytostome. Instead, 

 food apparently is ingested through pits in the unusually long groove. 

 A thick layer of ectoplasm in the anterior part of the body (Fig. 7. 9, 

 E, F) is a striking feature in Collinella, Nicollella, and Pycnothrix. 



