310 



ROTIFERA. 



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

 Dislyla 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 Rhixotic, corona Bdelloidic). Pterodina Ehbg. ; Pompholyx Gosse. 



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



armed with anterior and posterior 

 spines ; foot long, very flexible, wholly 

 retractile, wrinkled, ending in two 

 toes. Brachionus Ehrb., lacustrine 

 and marine ; Noteus, Notholca Gosse ; 

 Erctmia Gosse. 



Order 4. SCIRTOPODA. 



Swimming with velum, and skipping 

 with arthropodous limbs ; foot absent. 



Fam. 20. Pedalionidae. Six hollow 

 limbs ; head truncate, corona of two 

 concave lobes, and velum as in Philo- 

 ilinidiii' ; trophi malleo-ramate. Peda- 

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

 longest) ventro-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 Ncbalin. 



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. ,S't;iso?iGrube; 

 Paraseison Plate ; Saccobdella v. Ben. 

 and Hesse. 



GASTROTRICHA.t 



Small inpiiitic oi'i/anianis with a 

 double ventral row of cilia, a cuticle 



FIG. 250. Chactonotus maximus (after Btit- 

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

 oesophagus. 



* C. Clans, " Ueb. die Organisation, etc., der Gattung Seisou," Festschrift 

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

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



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



