SPIROTRICHA, OLIGOTRICHA 



653 



Genus Tontonia Faiire-Fremiet. With well-developed apical col- 

 lar; a long cytoplasmic (contractile) caudal process; salt water. 



T. gracilUma F.-F. (Fig. 307, e). 48-52^t long; caudal process 

 250-300/i long; macronucleus moniliform; with zoochlorellae. 



Fig. 307. a, Halteria grandinella, X490 (Kahl); b, //. g. var. cirrifera, 

 X370 (Kahl); c, H. g. var. chlorelligera, X260 (Kahl); d, Strombidium 

 calkinsi, X900 (Calkins); e, Tontonia gracilUma, X540 (Faure-Fremiet) ; 

 f, Strobilidium gijrans, X340 (Kahl); g, Tintinnidium fluviatile, Xl40 

 (Kent); h, i, T. semiciliatum , Xl40 (Sterki); j, Strombidinopsis gyrans, 

 X270 (Kent); k, Tintinnopsis cylindrata, X440 (Daday); 1, T. illinoisen- 

 sis, x420 (Hempel); m, Codonella crater a, X540 (Faure-Fremiet). 



Family 2 Strobilidiidae Kahl 



Genus Strobilidium Schewiakoff. Pyriform or turnip-shaped; cyto- 

 stome at anterior end; without cytopharynx; horseshoe-shaped 



