574 



THE INVERTEBRATA 

 .ten. 



|-£/-— /w..m. 



plx. 



Fig. 431. A view of Holothuria tubiilosa, somewhat diminished. The animal 

 is opened along the left dorsal interradius and the viscera are exposed. After 

 Ludwig. al. alimentary canal; a?np. ampullae of tentacles ; cl. cloaca; g. re- 

 productive organ; In.m. radial longitudinal muscle partly cut away; plx. 

 "dorsal blood plexus"; Po. Polian vesicle; ra.wv. radial water vessel; v.b. 

 " ventral blood vessel" ; re. respiratory trees ; stc. stone canals ; ten. tentacles ; 

 wvr. water vascular ring. 



