8 



('RINOII)K-K. 



,' 



^^S 



] , Part of an arm with two pinnae. 2, A single pinna. 3, One of the ten- 

 tacula. 4, Claw at the extremity of a pinna. 5, Claw of a filiform pro- 

 cess : all magnified. 



3. The arms are five, but bifurcate shortly after their 

 origin, each of the bifurcations being very long and taper- 

 ing to its extremity. Before bifurcating the arms are 

 simple ; but the bifurcations are pinnated with calcareous, 

 jointed, slender pinnse, which, when fully developed, con- 

 sist each of from twenty-two to twenty-four perforated 

 joints, and a claw of five or six crooked finger-like hooks 

 at the end. The joints are rough as if covered with short 

 spicule ; but the claws are smooth. The arms consist of 

 calcareous joints with sloping diagonal segments, which 

 can be separated from each other even as the joints can. 

 The joints of the pinnse are sometimes similarly con- 

 structed. In a full-grown Feather-star there are thirty- 

 four pinnse on each side of each bifurcation. 



