Yol. 55.] ECHIlfOIDEA AND OPHIUKOIDEA. 715 



trasted with the so-called Pelmatozoa, not so much by their 

 power of locomotion, for Antedon is a swift wanderer, as by the 

 character of their buccal armature and the absolute difference in 

 their method of obtaining nourishment. The Pelmatozoa obtain 

 their food as it were in molecules, by ciliary action ; the other 

 Echinodermata ingest it in larger masses by a prehensile mouth or 

 jaws.' A name is greatly needed to distinguish the Apelmatozoa, 

 and Megophagi might prove useful : it is physiological no doubt, 

 but it rests on a morphological character. If these suggestions were 

 to be adopted, our classification would stand thus : — 



ECHINODERMATA. 



MicROPHAGi or Pelmatozoa. 



Amphoralia. 

 * Cystoidea. 

 Blastoidea. 

 Crinoidea. 

 Agelocrinida. 



Megophagi (characterized by a buccal armature or prehensile 

 mouth). 



MoNOKCHiDA (without a buccal armature). 

 Holothuroidea. 



Pentoechida (with a buccal armature). 



Helkopoda (possessing adhesive tube-feet). 

 Asteroidea. 

 Echinoidea. 



Ophiuroidea (characterized by muscular arms). 



3a2 



