2(5 



THE ROTIFEEA. 



I have named these orders as follows : 



I. RHIZOTA (the rooted). Fixed when adult. 

 II. I3DKLL0IDA (tlie leech-like). That sw-im with their ciliary wreath, and creep like a leech. 



III. PLOIMA (the sea-worthy). That only swim with their ciliary wreath. 



IV. SCIKTOPOUA (the skii^ijers). That swim with their ciliary wreath, and skip with Artbropodous 



limbs. 



Now, the creatures contaiued m these orders, with a few exceptions, dilfer from each 

 other, first in their liabits, and secondly in the following points : 

 I. In the structure of the foot. 

 II. In the arrangement of the ciliary \\n:eath. 

 III. In the form of the trophi. 



I. In the structure of the foot. 

 (1) The Bhizotic foot is transversely wrinkled, and ends in a sort of sucking disk 

 (fig. IG) or cup (fig. 17). It is not retractile within the body, it never has telescopic 

 joints, nor is it ever furcate. 



Fig. IC— UhizDtic foot. 

 (^Floscuhuia atmpantdata) 



FiR. 17.— Rhizotic foot. 

 {Aldicerla Hnr/eii^) 



Fig. 18. - BcleUoidic toot. 

 (liott/er citnnu.-!) 



Fig. 19. — Scirtopodic foot. 

 {I'edalion mirum) 



(2) Tlie Bdcllo'ulic foot (fig. 18), on the contrary, is telescopic, retractile, furcate, and 

 is never transversely wrinkled, nor terminated by a suclring disk. 



(3) The Scirtopodic foot (fig. 19) is unique ; it is divided into two unconnected, 

 smooth, jointless styles, each ending in a ciliated expansion. 



(4) Tlie Plo'iinic foot is various in shape, but is always unlike that of any other 

 order ; for — 



(a) if transversely wrinkled, it is yet retractile within the body, and almost invari- 

 ably furcate ; 

 {h) if jointed and furcate, it is not also telescopic ; 

 (c) occasionally it is absent altogether. 

 II. In the arrangement of the ciliary wreath.' 

 (1) The Bhizotic ciliary wreath is of two forms : 



(a) The first encircles the body twice, by bending on itself; thus inclosing the 

 mouth, and having a dorsal gap between the points of flexure, figs. 20, 21. 



Fig. 20.— Rliizoiic wTcath ((r), front view. Fig. 21.- 

 ( Mclict-'rlfi nti'jfris) 



-Rhizotic wreath (f(), side view. 

 ( Mf.Ucef[n riii'jtrns ) 



Fig. 22.— Rhizotic wrentli (i), 



seen from alwve. 



( Floscularia campamtiatn ) 



' In figs. 20 to 25, cio is the ciliary wreath ; jiw is the principal wreath ; sic is the secondary wreath ; 

 6/ the buccal funnel ; l^) the lips. 



