HOLOTHURIOIDEA 



403 



very numerous deposits (Fig. 241, 3) are covered with nodules ; 

 they have usually only 4 holes, but larger, more irregular plates 

 also occur. In the superficial layer small, irregular, star-shaped 

 " cups " occur. Colour white or brownish. Does not grow to 

 a larger size than ca. 4 cm. 



It lives on stony or shell bottom or among calcareous algae, 

 from tide marks down to ca. 100 m. Development unknown. 



Fig. 241. — Deposits of Cucimiaria Planci (1), Cue. Norniani (2), and 

 Cue. lactea (3). x 190. 



But it has been observed to propagate by self -division. It is 

 eaten by various fishes — cod, haddock, plaice. 



In British seas this species is known from the south and west 

 coasts to the Shetland Islands, and on the east coast down to 

 Northumberland and Durham. It is known from Trondhjem- 

 fjord to Kattegat in Scandinavian seas ; to the south it is not 

 known south of Brittany. 



7. Cucumaria Planci v. Marenzeller. (Fig. 241, 1.) 



(Syn. Cucumaria doliolum Lamk., partim.) 



Body cylindrical or somewhat prismatic. Skin thick and 

 leathery, but smooth. Tube-feet in distinct double series in all 



coasts ; but a speci men sent to the author by Koehler proved to agree com- 

 pletely with C. lactea except in the brown colour ; it came from Plymouth. 

 Other browTi specimens from the north European seas examined by the 

 author likewise agreed with laetea, except in the colour. It seems evident 

 that Forbes's Genus hrunneus is nothing but a brown colour variety of 

 laetea, while the form described by Koehler under the name C. brunnea is 

 a different species, perhaps confined to the Mediterranean. 



