THE WHEEL ANIM.\LCULES (ROTATORIA) 591 



23 (22) Cuticula without many transverse folds. . Notoinmata Ehrenberg. 

 Many species. 



Representative species (Fig. 878). . . Notommata auritaEhrnnhQr^. 



(Fig. 881) N. torulosia Dujanlin 



(Fig. 857, A and 5, page 556). 



N. truncata Jennings. 



24(21) Very large, thick-bodied forms Co/>ew5 Gosse. 



Corona extending far on ventral surface. Few spedes. 



Representative species (Fig. 857, C, page 556, and Fig. 864, page 565). 



C opens pachyurns Gossc. 



25 (20) With three eyes Eosphora Ehrenberg. 



One large eye on brain; others small, in front. Few species. 



Representative species (Fig. 879). . . Eosphora digitata Ehrcnhcrg. 



26 (6) Two or four long bristle-like antennae on corona. Foot present or 



absent Family Synchaetidae . . 27 



Open- water rotifers; bodies short; foot short or absent; corona as broad as the broadest 

 part of the body, consisting mainly of a row of large cilia about the circumference. 



27 (28) Auricles present Synchaeta Ehrenberg. 



Body usually conical, largest at the head; foot short, rarely absent. About a dozen spedes. 



Representative species (Fig. 883). . . Synchaeta stylata Wierzcjski. 



(Fig. 880) S. tremuhi Ehr(.Til)crg. 



(Fig. 884) S. baltica Ehrenberg. 



28 (27) Auricles absent. No foot 29 



29 (30) With lateral oar-like swimming appendages. . Polyarthra Ehrenberg. 

 One species only (Fig. 882). . . . Polyarthra platyptera Ehrenberg. 



30(29) Appendages lacking \narthr a Hood. 



One species only (Fig. 885) Anarthra aptcra Hootl. 



31 (5, 64) Lorica always present. Corona small, not so broad, as a rule, as 



the broadest part of the lorica. Suborder Loricatina . . 32 



Foot present, short, not ringed; ending in two toes, or rarely one. 



32 (47) Lorica divided into plates by longitudinal furrows ^i 



