222 HOMOLOGIES. 



In no group of the Animal Kingdom is the 

 fertility of invention more striking than in 

 the Crinoids. They seem like the productions 

 of one who handles his work with an infinite 

 ea^e and delight, taking pleasure in presenting 

 the same thought under a thousand different as- 

 pects. Some new cut of the plates, some slight 

 change in their relative position, is constantly va- 

 rying their outlines, from a close cup to an open 

 crown, from the long pear-shaped oval of the 

 calyx in some to its circular or square or pentag- 

 onal form in others. An angle that is simple 

 in one projects by a fold of the surface and be* 

 conies a fluted column in another ; a plate that 

 was smooth but now has here a symmetrical figure 

 upon it drawn in beaded lines ; the stem which 

 is perfectly unbroken in one, except by the trans- 

 verse divisions common to them all, in the next 

 puts out feathery plumes at every such transverse 

 break. In some the plates of the stem are all 

 rigid and firmly soldered together ; in others they 

 are articulated upon each other in such a manner 

 as to give it the greatest flexibility, and allow 

 the seeming flower to wave and bend upon its 

 stalk. It would require an endless number of 

 illustrations to give even a faint idea of the vari- 

 ety of these fossil Crinoids. There is no change 

 that the fancy can suggest within the limits of 

 the same structure that does not find expression 



