INFUSORIA 



61 



Key to the families of Tlypotrichida here described : 



fli Body usuallj^ elongate and broad, with ventral cilia 1. Oxytriciiidae 



«2 Body more or less circular with very long bristles and cilia usually absent. 



2. EUPLOTIDAE 



Family 1. OXYTEICHIDAE. 



Body somewhat elongate with arched dorsal and flat ventral side, 

 the latter with cilia, bristles, etc.; mouth near the middle with an oral 

 groove running backwards: 21 genera; in fresh and salt water. 



Key to the genera of Oxytriciiidae here described: 



Oi Several median longitudinal rows of continuous cilia. 

 &i Five or more rows of cilia. 



Cj Mostly fresh-water animals 1. Urostyla 



Ca Marine animals 2. Epiclintes 



62 Less than 5 rows of cilia. 

 Cy Neither anterior nor anal bristles; body acute anteriorly. .3. SxiciiOTRicnA 

 C2 Such bristles present ; body usually broad. 



rfi Animals mostly marine. 4. Amphisia 



^2 Animals mostly in fresh water. 

 61 Two median rows of cilia. 



/i Three anterior and no anal bristles 5. Uroleptus 



fo No anterior bristles ; anal bristles present 7. Holosticiia 



Cn Three or 4 rows, body broad and rectangular^, 6. Onyciiodromus 



C2 No median rows of continuous cilia ; but marginal rows present. 



61 No caudal bristles 8. Oxytrictia 



62 Three long caudal bristles 9. Stylonychia 



1. Urostyla Ehrenberg. Body flexible, elliptical, 

 with longitudinal striations and rows of cilia; oral 

 groove at forw^ard end; 5 to 12 long anal bristles in 

 an oblique row, and 3 or more anterior bristles: 6 

 species; in fresh and salt water. 



U. trichota (Stokes) (Fig. 106). Length .3 mm.; 

 5 anal and about 20 anterior bristles: in fresh water. 



2. Epiclintes Stein. Body flexible, elongate, the 

 forward half being ovate, the hinder end slender and 

 cylindrical; several longitudinal rows of cilia: 1 

 species; marine. _ 



E. radiosa Quenner- 

 stedt (Fig. 107). Length 



.045 mm.; 5 large bristles at Fig. 101— Epiclintes radiosa 



forward end: Woods Hole. 



3. Stichotricha Perty. Body cylindrical and veiy contractile, 



with acute forward end; oral gTOove extending back to middle of 



body; 2 or 3 rows of cilia; color often green: 4 species; in fresh and 



salt water. 



S. secunda Perty (Fig. 108). Length .2 mm.: in fresh water. 



Fig. lOG 



Vrostjila tricJiota 

 (Conu). 



