ANIMAL KINGDOM. 



117 



times wanting, or exist only when extemporized for the occasion ; in 

 having no heart or circulating system, beyond a palpitating vesicle or 

 vacuole. Many of the Infusorians or Animalcules are here included. 



II. Radiates. — Having a radiate structure, like a flower, internally 

 as well as externally ; that is, having similar parts or organs repeated 

 around a vertical axis. The animals have a mouth and stomach for 

 eating and digestion, and hence they are widely diverse from plants, 

 although resembling them in their radiate arrangement of parts. 



Figs. 137 to 149 represent examples of Radiates : 137, an Actinia, 

 or Polyp ; 138, 139, living corals, the animals of which are polyps; 

 1 40, a Medusa or Acalepk, — also called Jelly-Jish, — showing well 

 the internal as well as external radiate structure, as the animal is 

 nearly transparent; 141, 142, polyp-like species of the class of Aca- 

 lephs ; 143, an Echinus, or Seaitrchin, — but not perfect, as the spines 

 which cover the shell and give origin to the name Echinus are re- 

 moved" from half its surface, to show the shell; 144, a Star-Jish ; 145, 

 146, Crinoids, — « animals like an inverted Star-fish or Echinus, stand- 



Figs. 137-146, 



142? 



Radiates, Figs. 137-146. 1. Polyps: Fig. 137, an Actinia ; 138, a coral, Dendrophyllia; 139, s 

 coral of the genus Gorgonia. 2. Acrdephs: 140 : a Medusa, genus Tiaropsis ; 141, Hydra (X 8); 

 142, Syncoryna. 3. Echinoderms : 143, Echinus, the spines removed from half the surface. 

 (X H)\ 144, Star-fish , Palpeaster Niagarensis ; 145, Crinoid, Encrinus liliiformis ; 146, Crinoid, 

 of the family of Cystids, Callocystites Jewettii. 



ing on a stem or pedicel, like a flower. Fig. 147, on the next page, 

 is the shell of another Sea-urchin ; and Fig. 1 48, another Crinoid. 

 Figs. 573 to 582 are additional examples of Radiates. 



The radiate feature exists not only in the external form, but also 

 in the interior structure. The mouth, when furnished with calcareous 



