310 



ROTIFERA. 



is much the larger ; foot jointed, furcate. Euchlanis Ehrb. ; Cathypna Gosse ; 

 Distyla Eckstein ; Monostyla Ehbg. 



Fam. 16. Coluridae. Body enclosed in a lorica, open at both ends, closed 

 dorsally, usually open or wanting ventrally ; head surmounted by a chitinous 

 hood ; toes two, rarely one, always exposed. Colurus Ehbg. ; Metopidia Ehbg. ; 

 Monura Ehbg. ; Mytilia Gosse ; Cochleare Gosse. 



Fain. 17. Pterodinidae. Lorica entire, various ; corona and velum those 

 of the Philodinidae ; trophi malleo-ramate ; foot wholly retractile, transversely 

 wrinkled, jointless, toeless, ending in a ciliated cup ; or foot absent ; (foot and 

 trophi Rhi/otic, corona Bdelloidic). Pterodina Ehbg. ; Pompholyx Gosse. 



Fam. 18. Brachionidae. Lorica box-lifte, open at each end, and generally 



armed with anterior and posterior 

 spmes ; foot long, very flexible, wholly 

 retractile, wrinkled, ending in two 

 toes. Brachionus Ehrb., lacustrine 

 and marine ; Noteus, Notholca Gosse ; 

 Eretmia Gosse. 



Order 4. SCIRTOPODA. 



Swimming with velum, and skipping 

 with arthropodo^ls limbs ; foot absent. 



Fam. 20. Pedalionidae. Six hollow 

 limbs ; head truncate, corona of two 

 concave lobes, and velum as in Philo- 

 dinidae; trophi malleo-ramate. Peda- 

 lion Hudson (Fig. 246), one limb (the 

 longest) Centre-median, another dorso- 

 median, and two pairs of lateral limbs ; 

 and two stylate ciliated appendages on 

 its posterior dorsal surface ; Hexarthra 

 Schmarda, with three pairs of limbs 

 attached to the ventral surface. 



Order 5. SEISONACEA.* 

 Marine forms parasitic on Nebalia. 

 The cloaca opens at base of neck in 



male, at hind end of body in female ; 



male otherwise like female. Intestine 



complete or blind. 



Fam. 21. Seisonidae. Seison Griibe ; 



Paraseison Plate ; Saccobdella v. Ben. 



and Hesse. 



GASTROTRICHA.f 



Small aquatic organisms with a 

 double ventral row of cilia, a cuticle 



* C. Claus, "Ueb. die Organisation, etc., der Gattung Seison," Festschrift 

 z. F. d. 25 j. Best. d. K. k. z. b. Gesellschaft, Wien, 1876. L. Plate, "Ectopar. 

 Rotatorien d. Golfes v. Neapel," Naples Mit., 7, 1886. 



f C. Zelinka, "Die Gastrotrichen," Z. f. w. Z., 49, 1890. 



FIG. 250.Chaetonotus maxlmus (after Biit- 

 schli), ventral view. Cb row of cilia ; Oe 

 oesophagus. 



