ECHINODERMATA 89 



Amphipholis squamata Delle Chiaje 



PLATE VI. Fig. 4, 5 



A very small viviparous brittle star with the 

 disc less than % inch in diameter and the very 

 slender arms about 2 inches long. Cosmopolitan, but 

 rare on the New Jersey coast. 



Amphioplus abditus Verrill 



Occurs at Woods Hole, Mass., and Nohank, 

 Conn., and also in Florida, but as yet has not been 

 found on the New Jersey coast, It burrows deeply 

 in mud. 



ECHINOIDEA 



(Sea Urchins, Sand Dollars, etc.) 



These animals are not pointed like the starfish 

 but rather are globular, hemispherical or discoid. 

 They are covered with spines which in the Sea 

 Urchins are usually long and prominent while in 

 some of the Sand Dollar type they are very minute. 



The internal anatomy of the Echinoids re- 

 sembles that of the starfish, but there is a coiled 

 digestive tube and certain modifications due to the 

 different shape of the test or shell. Many urchins 

 show a five pointed petaloid design on the test. Tube 

 feet are present as in the starfish ; however, some Sea 

 Urchins (as Arbacia) also move by walking on their 

 spines. 



Most Sea Urchins are vegetarians, or feed on 









