308 



ROTIFERA. 



FIG. 249. Trochosphaera acqnatoricdis (after Semper, from 

 Korschelt and Heider). Ce cloaca ; Dr glands of the 

 foregut ; Ex duct of the excretory organs ; G brain ; Ge 

 ovary and oviduct ; M mouth ; Mu muscles ; N nerve ; 

 S mastax; Si sense-organ; IT, preoral, W n postoral 

 ciliated band ; A cloacal orifice. 



obvious, Meliccrta ringens L. (Fig. 247) ; Limnias Schrank, tube without 

 pellets; Cejjhalosiphoii Ehrb., vent, antennae absent; Oecistes Ehrb., dors. 



ant. absent ; Lacinularia 

 Schweigger, adherent gela- 

 tinous tubes in clusters, 

 antennae absent ; Megalo- 

 trocha Ehrb. , clustered, 

 without tubes, ant. ab- 

 sent ; Trochosphaera Sem- 

 per (Fig. 249), solitary, 

 free-swimming, spherical, 

 velum as preoral ring 

 broken dorsally, ventral 

 antennae minute, trophi 

 malleo-ramate, lateral 

 canals end in cloaca, nerve 

 ganglion close to mastax, 

 male unknown, ovary 

 opens into cloaca. Fresh 

 water of Philippine 

 Islands. Interesting from 

 its resemblance in form, 

 gut, velum, and appear- 

 ance to a trochosphere 

 larva ; Conochilus Ehrb. , 

 gap in velum ventral. 



Order 2. BDELLOIDA. 



Swimming with their velum, and creeping like a leech. Foot telescopic, wholly 

 retractile within the body, usually ending in three toes. 



Fam. 3. Philodinidae. Corona a pair of circular lobes, transversely placed. 

 Velum a continuous marginal curve, bent on itself at the dorsal surface so 

 as to encircle the corona twice, with the mouth between its upper and lower 

 curves, and having also two gaps, the one dorsal between its points of flexure, 

 and the other ventral in the upper curve opposite to the mouth (Fig. 245, 4) ', 

 trophi ramate. Philodina Ehrb., eyes two, cervical ; Rotifer Schrank, eyes two, 

 within the frontal column ; in both these genera no oviduct has been seen, but 

 the eggs develop in the body-cavity, and both eggs and young have been seen 

 to leave the cloaca ; males not known. Actinurus Ehrb. ; Callidina Ehrb. 



Fam. 4. Adinetidae. Corona a flat prone surface ; velum as the furred 

 (with cilia) ventral surface of the corona ; trophi ramate ; frontal column 

 soldered to dorsal surface, and ending in two hooks. Adineta Hudson. 



Order 3. PLOIMA. 



Swimming with their velum, and (in some cases) creeping with their toes. 

 The mastax can be protruded so as to seize the prey ; the ganglion is well 

 developed and the eyes often have lenses. 



Sub-order 1. ILLORICATA. 



Integument flexible, not stiffened to an enclosing shell ; foot when present 

 almost always furcate, but not transversely wrinkled, rarely more than feebly 

 telescopic, and partially retractile. 



