72 ECHINODERMATA. 



Psolinus (Forbes). Body irregular, ovate, curved, 

 with five rows of distant suckers, the under ones 

 always bent ; tentacles ten ; dental apparatus 

 short, truncate ; no gizzard. 



P. brevis. Fig. 114 ; f . 



FAMILY II. THYONID^E. 



Thyone (Oken). Body nearly regular, covered 

 with scattered wart-like suckers ; tentacles ten ; 

 teeth long and thread-like. 



T. papillosa. Fig. 115 ; n. s. T. Portlockii. 



raphanus. 



Holothuria (Linn.). Body lengthened, soft, 

 nearly cylindrical, covered with scattered suckers ; 

 tentacles twenty; vent widely open. 



H. nigra. Fig. 116 ; . 

 intestinalis. 

 tubulosa. 



