394 ECHINODERMS OF THE BRITISH ISLES 



it is even stated to be of " all shades, from sienna to rose- 

 colour and delicate pink '' (Peach), (irons to a considerable size, 

 up to ca. 20 cm. length. 



It is a shallow-water species, apparently apt to climb rock 

 walls. When irritated it throws out its Cuvierian organs, which, 



Fig. 234. — Holothuria For^ikali ; dorsal (upper figure) and ventral side 

 (lower figure). Much reduced. 



in the shape of long, white, sticky threads, dart through the water 

 like arrows, entangling the objects they come into touch with. 

 The larva is an Auricularia of very simple shape, and with a star- 

 shaped calcareous body in the pos- 

 terior end. Breeding season in the 

 summer months. The parasitic fish 

 Fierasfer is found in this species, at 

 least in the Mediterranean. 



In British seas this species is 

 fairly common along the south-west 

 coast of England and the west coast 

 of Ireland, from the Kenmare River to Donegal, from between 

 tide-marks to a depth of ca. 50 m. Also recorded from the west 

 coast of Scotland (Sleat Sound). It is elsewhere found along the 

 Atlantic coasts of Europe and in the Mediterranean. The 

 greatest depth from w^hich it has been recorded is 68 m. 



Fig. 235.— Deposits of Holo 

 thuria Forskali. x 450 

 (After Bell, Catalogue Brit. 

 Echinod. ) 



III. Order. Dendrochirota Grube. 



Tube-feet present ; tentacles tree-shaped ; tentacle ampulla) 

 absent or small. Retractor muscles usually present. Respiratory 

 trees present, sometimes connected with the alimentary canal 

 through a rete mirabile. Stone canal hanging free in the body 

 cavity. Mesentery of the posterior intestinal loop in left or 

 right ventral interradius. Gonads on both sides of the dorsal 



