56 



Fresh-water Biology 



{Continued from page 55) 



4 — One larger and one secondary flagellum; body flexible (fig. 25, PI. 21) Astacia 



— One evident flagellum 5 



5 — Colorless flexible species (fig. 19, PI. 21) Peranema 



— Species typically green, with cuticula. Flexible with red eye spot (fig. 6), Euglena; 

 not flexible, flattened striate (fig. 11) Phacus 



6 — Solitary. Colorless, 2 flagella, with pharynx, body slightly flattened, Chilomonas; 



colored, 4 flagella (fig. 1), Carteria; green, 2 flagella, spherical (fig. 4) 



Chlamydomonas 



— Colonial. With 2 brown band like chromatophores, spherical colonies (fig. 15) Synura; 

 With green chromatophores (see Volvocaceae, page 44). 



ROTIFERA* 



1 — Head and foot telescopic retractile, body ringed, movements leech like, lateral palpi 



wanting 2 



— Head and foot not telescopic retractile, not leech like, lateral palpi usually distinct. .3 



2 — Corona two circular retractile lobes. Eye in neck (fig. 1) Philodina; eye in proboscis 



(fig. 2, 3) Rotifer; eyes absent Callidina 



— Corona a fiat ventral ciliated disc (fig. 4) Adineta 



3 — Adult animals attached, or in colonies; if separate, usually in tubes 4 



— Not fixed when adult; rarely in tubular case 8 



4 — Corona with long setae or cilia, or both 5 



— Corona without setas. Body elongate, Acyliis: body short (fig. 7), (Cupelopagis) 

 Apsilus. 



5 — Corona with long slender setae. Setae scattered on lobe of corona (fig. 5) (Collotheca 



Floscularia: setae in whorls or rows (fig. 6) Stephanoceros 



— Corona with strong conspicuous moving cilia 6 



{Continued on page 58) 



* Adapted from Keys given by Jennings, Collin, et al. 



Plate 23. Rotifers 



Adineta, 4 

 Anapus, 40 

 Anursea, 35, 36 

 Apsilus, 7 

 Asplanchna, 13 

 Brachionus, 30 

 Colurus, 27 

 Conochilus, 9 

 Diglena, 19 

 Dinocharis, 22 

 Diurella, 20 

 Euchlanis, 25 

 Floscularia, 5 

 Forcipate jaws, 39 

 Gastropus, 38 

 Hydatina, 17 

 Malleate jaws, 31 

 Malleo-ramate jaws, 11 

 Melicerta, 8 



Microcodon, 12 

 Monostyla, 26 

 Noteus, 32 

 Notholca, 33, 34 

 Pedalion, 41 

 Philodina, 1 

 Plcesoma, 37 

 Polyarthra, 18 

 Pterodina, 28, 29 

 Ramate jaws, 10 

 Rattulus, 21 

 Rotifer, 2, 3 

 Salpina, 23, 24 

 Stephanoceros, 6 

 Synchaeta, 14, 15 

 Triarthra, 16 



