ROTIFERA FLOSCULARIANS AND ME LIC E RTI ANS. 433 



with the presence, ahsence, and conformation of the foot (or tail), 

 are made to furnish the characters of the subordinate groups. 

 Either of the two latter is certainly more natural than the first, 

 as bringing together for the most part the forms which most 

 agree in general organization, and separating those which differ; 

 and we shall adopt that of M. Dujardin as most suitable to our 

 present purpose. 



I. The first group includes those that habitually live attached 

 by the foot, which is prolonged into a pedicle ; and it includes 

 two families, the Floscularians and the Melicertians, both of which 

 bear a certain general resemblance to the Vorticellince ( 268) on 

 the one hand, and to Zoophytes (Chap. XI) on the other. For 

 they are commonly found attached to the stems and leaves of 

 aquatic plants, by a long pedicle or footstalk, which bears a 

 somewhat bell-shaped body; and in one of the most beautiful 

 species, the Stephanoceros Eichornii (Fig. 202), this body has five 

 long tentacles, beset with tufts of short bristly cilia, reminding 

 us of the ciliated tentacles of the Bryozoa (Chap. XIII), whilst 

 the body seems to be enclosed in a cylindrical cell, resembling 

 that of Hydrozoa and Bryozoa. ' A comparison of this with other 

 forms, however, shows that these tentacles are only extensions of 

 the ciliated lobes which are common to all the members of these 

 families; and the so-called "cell" is not formed by a thickening 

 and separation of the outer tegument, but by a gelatinous secre- 

 tion from it; so that, as the rest of the organization is essentially 

 conformable to the Rotiferous type, no such passage is really 

 established by this animal towards other groups, as it is com- 

 monly supposed to form. In one respect, Floscularia is still more 

 aberrant; for the long bristly filaments with which its lobes are 

 beset, are not capable of rhythmical vibration, and cannot, there- 

 fore, be properly termed " cilia." The body of M elicerta is pro- 

 tected by a most curious cylindrical tube, composed of little 

 rounded pellets agglutinated together ; this is obviously an arti- 

 ficial construction ; and Mr. Gosse has been fortunate enough to 

 have an opportunity of watching the animal whilst engaged in 

 building it up. Beneath a projection on its head which he terms 

 the chin, there is observed a small disk-like organ, in which, 

 when the wheels are at work, a movement is seen very much 

 resembling that of a revolving ventilator. Towards this disk, 

 the greater proportion of the solid particles that may be drawn 

 from the surrounding liquid into the vortex of the wheel-organs, 

 are driven by their ciliary movement, a small part only being 

 taken into the alimentary canal; and there they accumulate, 

 until the aggregation (probably cemented by a glutinous secretion 

 furnished by the organ itself) acquires the size and form of one 

 of the globular pellets of the case ; the time ordinarily required 

 being about three minutes. The head of the animal then bends 

 itself down, the pellet-disk is applied to the edge of the tube, the 

 newly formed pellet is left attached there, and, the head being 



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