ASTERIAS. 67 







Order 2. Pedata. 



Ambulacral feet in rows or scattered. (Thyone, 



Cucumaria.) 

 Order 3. Apoda. 



Without tube feet. Worm-like. (Synaptula.) 

 CLASS 5. Crinoidea. 



Temporarily or permanently attached by a 



stalk. With five branching arms radiating 



from a small disk. 

 Order 1. Neo-Crinoidea. 



Characters as above. (Antedon, Pentacrinus.) 



Berry: Metamorphosis of Echinoderms. Quart. Jour. Mic. Sci., 38, 1905. 

 Coe: Echinoderms of Connecticut. State Geol. and Nat. Hist. Sun., 19, 



1912. 

 Grave: Occurrence among Echinoderms of Larva? with Cilia Arranged in 



Transverse Rings. Biol. Bui., 5, 1903. 

 Tennent: Echinoderm Hybridization. Carnegie Inst., 132, 1912. 



ASTEROIDEA. 



ASTERIAS. (Starfish.) 



Starfishes are rather common along most coasts and are 

 among the worst enemies of oysters, muscles, clams, and bar- 

 nacles. They occasionally capture fish in aquaria. They can 

 generally be most satisfactorily examined on shallow-water 

 mussel-beds or on rocks covered with barnacles. Places where 

 starfish occur should be visited, and the conditions under which 

 they live examined. Determine: 



1. How they feed. 



2. What their enemies must be. 



3. How their arms are repaired when injured. Do you find 

 specimens that are growing new tips to injured arms or are such 

 arms apparently replaced? When an arm is injured how must 

 the animal proceed to repair it? 



4. Do specimens ever conceal themselves? See if specimens 

 can be found with pieces of grass and weeds covering them. 

 Try picking these pieces off to see if they adhere. 



5. Do the animals have other means of protection? 

 Examine a specimen and notice: 



1. That the surface by which the animal clings, the oral 



