HOLOTHURIOIDEA 



363 



with full certainty mthout a microscopical examination of their 

 calcareous deposits.) L. violacea is of world-wide distribution, 

 being known from the Davis Strait to the Azores and the African 

 coast, and from the Indian Ocean to AustraUa and Japan. 

 Bathymetrical distribution ca. 225-1800 m. 



2. Benthogone Koehler. 



Mouth ventral ; tentacles 15-20, retractile. Ventro- lateral 

 ambulacra with a single row of retractile tube-feet, mid-ventral 

 ambulacrum naked. Dorsal ambulacra each with a single or 

 double row of small, retractile papillae. Calcareous deposits 

 wheels and simple rods. 



Only one species known from the British (and N.E. Atlantic) 

 seas. 



1. Benthogone rosea Koehler. (Fig. 215.) 



Body flattened or more or less cyHndrical. The tentacles, 

 which vary in number from 15-20 (mostly 18), are surrounded by 

 a circular area limited by a circle of small papillae. Tube-feet 



;€ ■ €)> 5> {C -O ^ r^ 





Fig. 215. Benthogone rosea ; dorsal and ventral side. Reduced. 



(After Perrier, " Talisman " Holothurioidea.) 



and dorsal papilla? not very close set, the latter in an indistinct 

 double series. Wheels (Fig. 216) of one sort only, 006-0- 16 mm. 

 in diameter. The tube-feet and papillae contain simple, more or 

 less thorny rods, besides the wheels ; no terminal disk in the 

 tube-feet. Small nodules apparently only in the skin of the 



