INVERTEBRATE BOTTOM FAUNA 



519 



^^pr '"^^^^ 



abundance. The sea-slugs Stichopus tremulits and Mesothuria 

 intestinalis so charac- 

 teristic of the deep 

 parts of our fjords, are 

 entirely absent, but in- 

 stead of these forms 

 with foot-suckers we 

 have a footless genus 

 TrocJiostonia (see Fig. 

 361). The sea-mice 

 are represented by 

 Pourtalesia (see Fig. 

 362), a very remark- 

 able genus that in 

 some respects re- 

 sembles forms long 

 extinct, but Spatangus, 

 Ech in oca rdui ;?z and 

 Brissopsis (character- fig. 359. 



istic of our fiords and BathyHastervexillifer,^y.Thoms. Reduced. (After Bell. ) 



coast-banks), and the ordinary sea-urchins are no longer to be 



found. Huge sea- 

 lilies or feather- 

 stars [Antedon 

 esckrickti, see Fig. 

 363, and A. pro- 

 /za'rt;), and quantities 

 of the medusa's 

 head [Gorgono- 

 cephalus eiicnemis), 

 are attached most 

 likely either to Um- 

 belhda or to the 

 numerous sponges, 

 Cladorhiza sp., 

 whose hard central 

 axis and tree -like 

 ramifying shape 

 make it so conspic- 

 uous, someof which 

 sometimes form 

 regular thickets 

 There are gigantic representatives of the 



Fig. 360. 

 Hytnenasier pellitcidus, Wy. Thorns, 



Michael Sars, 



along the bottom. 



