5*4 



CCELENTERA TES. 



Umbdhda thomsoni (nat. size) 



sixty miles from the coast of Greenland. The polyp-stocks consisted of a long, 

 thin stem, ending in a bundle of polyps. The larger specimen was two yards long. 



These two 

 specimens, soon 

 after being 

 described, were 

 lost, but a very 

 1 similar form 

 -?„ - (IT. thomsoni) 

 f|^ X \ was obtained 

 during the 

 Challenger ex- 

 pedition ; and 

 other species have been 

 discovered in various lati- 

 tudes, at great depths. - 

 Two were found between 

 Portugal and Madeira, at 

 two thousand one hundred 

 and twenty fathoms, while 

 U. leptocaidis was taken in 

 the Indian Ocean, some two 

 thousand five hundred 

 fathoms below the surface. 

 The accompanying illustra- 

 tion shows a species (U. 

 encrinus) from the northern 

 seas. 



Another family of 

 eight -rayed corals is that 

 of the sea -fans, or Gorgo- 

 niidce, of which the beauti- 

 ful, horny, tree, and bush- 

 like growths give no idea of the living coral. In 

 order to gain an idea of the latter, we must picture 

 these trees thickly covered with beautiful eight-rayed 

 anemones. As in the case of ordinary corals, the 

 polyps secrete the horny branches beneath their bases, 

 and on these they rise in gracefully branching colonies. 

 All the sea-fans are attached, and branch in the most 

 various ways, some in all directions, others only in one 

 plane ; in some cases simple branches run out at an 

 angle or spirally, forming fans or nets, etc. In most, 

 the axis is horny and flexible, and they might be 

 called horny corals, but single calcareous particles are 

 enclosed in the axis, and its soft covering is crowded UiribelMa encrinus (nat. size). 



