70 



ECHINODERMATA. 



Brissus (Klein). Body heart-shaped, convex; 

 avenues as in Spatangus ; a dorsal impression en- 

 closing the upper avenues. 



B. lyrifer. Fig. 110; i. 



Amphidotus (Agass.). Body heart-shaped, con- 

 vex ; four of the dorsal avenues truncate, oblong, 

 with an impression within them; impression under 

 the vent oval or heart-shaped. 



A. cordatus. Fig. Ill ; ^. 



A. roseus. 



Order II HOLOTHUROIDEA. 



Suckers arranged in five regular rows ; 

 body angular Pentactada. 



Suckers scattered over the whole surface ; 

 body cylindrical ThyonidcE. 



