CHARACTERISTIC DEEP-SEA TYPES. OPHIURANS. 109 



North of Cape Hatteras the species of starfish procured by the 

 " Blake " are identical with those described by Professor Verrill 

 from the dredgings of the United States Fish Commission. 



I would only mention here, as the most interesting of the 

 species we found, ten-armed specimens of Brisinga coronata. 

 (Fig. 387.) This species forms the subject of an elaborate 

 paper by the younger Sars, and I have here reproduced one of 

 his figures. 



OPHIURANS. 1 



Among Echinoderms there are two families, the brittle-stars, 

 or Ophiuridae, and the branching-stars, or Astrophytidae, which 

 are distinguished by a peculiar axis in the arms, made up of 

 articulated bones somewhat like vertebrae. The disk or body is 



Fig. 389. Ophiocreas spinulosus. ^. 



usually distinctly set off from the arms. These last contain no 

 prolongation of the central digestive cavity, as they do in the 

 starfishes proper. 



3 Mr. Lymau has prepared the account of the ophiurans. 



