THE WHEEL ANIMALCULES (ROTATORLK) 6ll 



104 (103) Corona drawn out into long pointed arms, which bear cilia arranged 



in whorls Stephanoceros Ehrenberg 



One species only (Fig. 937). . Stephanoceros eichhornii Ehrcnbcrg 



105 (102) No cilia on corona Family Apsilidae 



106 



106 (107, 108) Body short, sac-like Apsiliis MetschnikofT. 



Corona a large sac or chamber; no foot; attached by an adhesive disk. Two or three spedes. 



Representative species (Fig. 938). . . . Apsiliis hucincdax Forbes. 



107 (106, 108) Body longer, fusiform, a narrowed neck separating off a 



conical anterior part Atroclnis Wicrzcjski. 



Corona a membranous ring with five short lobes bearing tentacles. 



Only one species (Fig. 939). . Atrochus tentaculatus VVierzejski. 



108 (106, 107) Body long, with a long, slender, tapering stalk. 



Acyclus Leidy. 

 Corona with but one large dorsal lobe. Living in colonies of Megalotrocha dboflavicans . 



Representative species (Fig. 941) Acyclus inquictus Leidy. 



109 (2) Corona surrounded by two parallel wreaths of cilia with a furrow be- 



tween. CiUa of outer wreath always shorter than those of 

 inner. 



Order Melicertida . . no 



The furrow between the wreaths of cilia sometimes clothed with short cilia. Jaws malleo- 

 ramate (Fig. 866). Foot never ending in two toes side by side; sometimes lacking. Eyes two, 

 rarely absent. Fixed or free swimming; the free-swimming species often without foot and 

 frequently bearing appendages on the body. 



no (121) Free swimming and not in tubes or in colonies. .... n i 



111 (120) Not spherical . . iii 



112 (115) With a lorica. Without appendages. 



Family Pterodinid.\e . . nj 



113 (114) Foot present, long, ringed, ending in a bunch of cilia. 



Pkrodina Ehrcnbcrg. 



Lorica more or less flattened dorso-ventrally. Many species. 



Representative species (Fig. 942). . • Pterodina pal i mi EhrenUTc 

 (Fig. 866, B, page 575)- • ^' <''^'<''' Parson.v 



n4 (n3) No foot Pompholyx Gosse. 



Lorica not flat. Two or three species 



Representative species (Fig. 940). . . Pompholyx com pUfUa i.)o6&c. 



