OPHIURID,E. 275 



attaches itself to various kinds of sea-weed, and other 

 submarine objects. 



The adult Comatula generally measures about five 

 inches across its fully expanded rays. 



Before treating of what are termed the true Star- 

 fishes, we require to dwell briefly upon an inter- 

 mediate family named by Professor Forbes the 

 Ophiuridce, 'from the long serpent or worm-like 

 arms, which are appended to their round, depressed, 

 urchin like bodies. . . . They hold the same relation 

 to the Crinoidea that the true Star-fishes hold to 

 the Sea -Urchins. They are spinigrade animals, and 

 have no true suckers by which to walk, their pro- 

 gression being effected (and with great facility) by 

 means of five long flexible -jointed processes placed 

 at regular distances around their body, and furnished 

 with spines on the sides and membraneous tentacula. 

 These processes are very different from the arms of 

 the true Star-fishes, which are lobes of the animal's 

 body, whereas the arms of the Ophiuridse are super- 

 added to the body, and there is no excavation in 

 them for any longation of the digestive organs/* 



The British Ophiuridso are now classed under two 

 genera ; of the Ophiurse, or Sand-stars only two 

 species (0. texturata and 0. albida) are found on 

 onr shores; and the Ophicomse, or Brittle-stars, of 

 which there are ten. 



* British Star-fishes. 



