386 Ciliophora 



Fig. 7. 31. A-C. Cross-section of Metopus sigmoides through the anterior 

 part of the peristome and more posterior levels, showing some of the 

 membranelles (A, B) and the undulating membrane; x815 (after Wetzel). 

 D, E. Peritromus kahli Villeneuve-Brachon: ventral view, x300; sagittal sec- 

 tion, schematic, x450 (after V-B.). F. Plagiotoma lumbrici Dujardin, showing 

 adoral ciliation, somatic cilia (schematic), and a contractile vacuole; x240 

 approx. (from Kent, after Stein). G. Caenoniorpha medusula Perty, showing 

 ciliary pattern and bases of membranelles; x450 (after Villeneuve-Brachon). 

 H. Spirorhynchus verrucosa da Cimha, x425 (after Kirby). I. Metopus 

 mathiasi Villeneuve-Brachon, ventral view, x375 (after V-B.). J. Lichnophora 

 macfarlandi Stevens, showing basal and peristomial discs, adoral ciliation, 

 lateral membrane extending toward cytostome; x565 (after Balamuth). 



scattered bristles, and in some cases, so-called mucilaginous trichocysts. 

 The band of membranelles extends across the anterior end or antero- 

 ventral surface and then posteriorly along the left ventral margin to the 

 cytostome, usually near the middle of the body. 



