54 



STARFISH GALLERY. 



Fisr. 34. 



A. Anchor and plate of Synapta. B ; C. Tables of Holothuria impatiens ; 

 and D. Holothuria atra : from various aspects. E. Spicule from 

 sucker of Stichopus variegatus, (Magnified about 200 diam.). 



Fix. 35. 



Diagram of Water-vessels. 



cc. Circular canal, with p.v, its Polian vesicles ; from it a radial canal (v.c.) 

 is given off along the lower surface of each arm ; this supplies, by side 

 brandies, the suckers, s ; connected with each sucker is a contractile 

 swelling or ampulla (a). The circular canal is in connection with the 

 exterior by s.c, the stone-canal, and opens to it by the madreporite {in). 



