ROTIFERA 



93 



Order II. Bdelloida. 



Forms which swim and creep like a leech ; foot retractile 

 jointed, telescopic, termination furcate. 



Fam. 3. PHILODIXAD.S. PhUodina, Rotifer, Callidina. 



Order III. Ploima. 

 Forms which swim only. 



Grade A. ILLORICATA. 



Fam. 4. HYDATIXAD.&. Hydatina, Ehinops. 

 Fam. 5. SYXCHJJTAD.E. Synchsta, PolyarAra. 

 Fam. 6. NOTOJIMATAD.S. Notonimata, Diglena, Furcularia, 



Scandium, Pleurotrocha, Distemma. 

 Fam. 7. TRIARTHUAD.K. -friarthra. 

 Fam. 8. ASPLAXCHXAD.S. Asplanchn 



Grade B. LOEICATA. 

 Fam. 9. BRACHIONID.E. Brachionus, Noteus, Anursa, Sac- 



culus. 



Fam. 10. PrERODlNADjE. Ptcrodina, Pompholyx. 

 Fam. 11. EUCHLAXID.E. Euchlanis, Salpina, Diplax, Mono- 



stylo,, Colurus, Monura, lletopodia, Stephanops, Monocerca, 



Mastigocerca, Dinocharis. 



Order IV. Scirtopoda. 



Forms which swim with their ciliary wreath, and skip by means 

 of hollow limbs with internal locomotor muscles. 



Fani. 12. PEDALIONIDJB. Pedalion. 



The above list includes only the principal genera. There are, 

 however, a number of forms which could not be placed in any of 

 the above families. 



ABERRANT FORMS. 



Trochosphxra sequatorialis (fig. 6, G), found by Semper 

 in the Philippine Islands, closely resembles a monotrochal 



FIG. 6. Various aberrant forms. A, Balatro talrta (after Claparede) : a, mastax. 

 B. Seison ndsalite (after Clans) : m, month ; rd, position of the aperture of the 

 vas dcfcrcns. C. Lindia torulcta: a, ciliated processes at the sides of the heat 

 representing cephalotroch ; of, eye-spots. D, E, and F, Apsilta lentiformit 

 (after Mecznikow). D, adult female with expanded proboscis: m, position of 

 the mouth : *, lateral sense-organs. E. yonng free-swimming female. F. adult 

 male. G, Trochotphxra Kquatorialit (after Semper) : m, mouth ; y, ganglion : 

 n, anus; 6, velum; oc, eye-spot; c, muscles. 



polychsetons larva while possessing undoubtedly Rotiferal 

 characters. Mecznikow has described a remarkable form, 

 Apsilus lentiformis (fig. 6, D, E, and F), the adult female 

 of which is entirely devoid of cilia but possesses a sort of 

 retractile hood ; the young female and the males are not 

 thus modified. Claparede discovered fixed to the bodies 

 of small Oligochaetes a curious non-ciliated form, Balatro 

 calvus (fig. 6, A), which has a worm-like very contractile 

 body and a well-developed mastax. As mentioned above, 

 the ciliatiou is reduced to a minimum in the curious worm- 

 like form Lindia (fig. 6, c). Seison nebalix (fig. 6, B), 

 living on the surface of Ifebalix, which was described 

 originally by Grube, is the same form as the Satcobdella 

 nebalise, which was supposed by Van Beneden and Hesse 

 to be a leech. It has been shown by Glaus to be merely 

 an aberrant Rotifer. 



Of the curious aquatic forms Idhydium, Chsetonotus, 

 Turbanella, Dasyditis, Cephalidium, Chxtura, and Hemi- 

 dasys, which Mecznikow and Claparede included under 

 the name Gastrotricha, no further account can be given 

 here. They are possibly allied to the Rotifera, but are 

 devoid of mastax and trochal disk. 



Bibliography, 



The following are some of the more important memoirs, &c., on 

 the Rotifera. 



(1) Leenwenhoek, Phil. Trans., 1701-1704. 



(2) TZhieu\XTg,DieInfusiimst}iierche>ialsvollkommeneOrganisme>i, 



1838. 



(3) II. F. Dujanlin, Hist. Nat. des Zoophytes: Infusoires, ]841. 



(4) W. C. Williamson, " On Mclicerta ringens," Quart. Jour. 



Micr. Sci., 1853. 



(5) Ph. H. Gosse, "On Mtlieerta ringens," Quart. Jour. Micr. 



Sci., 1853. 



(6) T. H. Huxley, "OnLaeinulariasocialis," Trans. Micr. Soc., 



1853. 



(7) FT. Leydig, " Ueber den Ban nnd die systematische Stellung 



der Raderthiere," Zeit. /. w. Zool., vi., 1854. 



(8) Ph. H. Gosse, Phil. Trans., 1856. 



(9) F. Cohn, Zeit.f. w. Zoo!., vii., ix., and xiL 



(10) Ph. H. Gosse, Phil. Trans., 1858. 



(11) Pritchard, Infusoria, 1861. 



(12, 13, 14) C. T. Hudson, " On Pedalion," Quart. Jour. Micr. 

 Sci., 1872, and Monthly Micr. Jour., 1871 and 1872. 



(15) E. Ray Lankester, "On Pedalion," Quart. Jour. Sci., 1872. 



(16) El. Mecznikow, "On Apsilus Itntiformis," Zeit^f. w. Zool., 



1872. 



(17) C. Semper, "On Trochosphasra," Zeit. f. w. Zool., xxiL. 



1872. 



(18) K. Eckstein, "Die Rotatorien der Umgegend von Giessen," 



Zcit.f. w. Zool., 1883. 



(19) C. T. Hudson, "On an Attempt to reclassify Rotifers," 



Quart. Jour. Micr. Sci., 1884. 



(A. G. B.) 



