ROTIFERA 



93 



Order II.— Bdelloida. 



Forms which swim and creep like a leech ; foot retractile 

 jointed, telescopic, termination furcate. 



Fam. 3. PHiiODiNADiE. FhUodina, Rotifer, CalUdina. 



Order III.— Ploima. 



Forms which swim only. 



Grade A. Illoricata. 

 Fam. 4. Hydatinad^. Hydaiina, Ehinops. 

 Fam. 6. SYNCHiETADiE. Synchseta, Polyarthra. 

 Fam. 6. NoTOMMATADiE. NQtommata, Diglena, Furcularia, 



Scaridium, Pleurotrocha, Distemma. 

 Fam. 7. TKiARTHiiADiB. Triarthra. 

 Fam. 8. Asplanchnad^. Asplanchn 



Grade B. LoaiCATA. 

 Fam. 9. BEACHioNiDiE. Brachionus, Noieus, Anwxa, Sac- 



culv^. 

 Fam. 10. Ptekodinada Pterodina, Pompholyx. 

 Fam. 11. EuCHLANiD^. Euchlanis, Salpina, Diplax, Mono- 



styla, Colv/rus, Monura, Metopodia, Stephanops, Monocerca, 



MasHgocerca, Dinocharis. 



Order IV. — Soirtopoda. 

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

 of hollow limbs with internal locomotor muscles. 

 Fam. 12. Pedalionid*. 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. 



Abeeeant Foems. 

 Trochosphsera seqttatorialis (fig. 6, g), found by Semper 

 in the Philippine Islands, closely resembles a nionotrochal 



Fig. 6. — -Various aben'ant forms. A, 5aZa(roca;vtt5 (after Claparfede): a, inastax. 

 B, Seison nehaliis (after Claus) : m, mouth ; wd, position of the apei"ture of tiic 

 vas deferens. C, Lindia torulosa: a, ciliated processes at the sides of the head 

 representing cephalotroch; oc^ eye-spots. 1), E, and F, Apsilus lentiformis 

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

 the mouth; s, lateral sense-organs. E, young free-swimming female. F, adult 

 male. G, Trochosphsera teqaatorialis (after Semper) : m, mouth ; g, ganglion ; 

 a, anus; b, velum; oc, eye-spot; c, muscles. 



polychsetous larva while possessing undoubtedly Botiferal 

 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 Oligochsetes 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 ciliation is reduced to a minimum in the curious worm- 

 like form Lindia (fig. 6, c). Seison nebalise (fig. 6, b), 

 living on the surface of Nebalix, which was described 

 originally by Grube, is the same form as the Sa-ccohdella 

 nehalix, which was supposed by Van Beneden and Hesse 

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

 an aberrant Rotifer. 



Of the curious aquatic forms Idhydium, Ghxtonotus, 

 Turhanella, Dasyditis, Gephcdidium, Ghxtura, and Hemi- 

 dasys, which Mecznikow and Claparfede included under 

 the name Gastrotricha, no further account can be given 

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

 devoid of mastax and trochal disk. 



Bibliography. 

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

 the Potifera. 



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



(2) EhienheTgiDielnfusionsthierchenalsvollkoinmeneOrganismen, 



1838. 



(3) M. F. Dujardin, Bist. Nat. des Zoophytes : Infusoires, 1841. 



(4) AV. C. Williamson, " On Melicerta ringens," Quart. Jour. 



Micr. Sci., 1853. 



(5) Ph. H. Gosse, "On Melicerta ringeiis," Quart. Jour. Micr. 



Sci., 1853. 



(6) T. H. Huxley, "Oa Lacinularia socialis," Trans. Micr. Soc, 



1853. 



(7) Fr. Leydig, " Ueber den Ban und die systematische Stellung 



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



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



(9) F. Cohn, Zeit.f. w. Zool., vii., ix., and xii. 



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



(11) Pritchard, Infusoria, 1861. 



(12, 13, 14) 0. 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 lentiformis," Zeit. f. w. Zool., 



1872. 



(17) C. Semper, "On Trochosphsera," Zeit. f. w. Zool., xxii.. 



1872. 



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



Zeit.f. w. Zool., 1883. 



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



QumH. Jour. Micr. Sci., 1884. 



(A. G. B.) 



