REPOET ON THE OPHIUROIDEA. 205 



Gorgonocephalus austraUs, Lym. 



Astrophyton australe, Vll., Contrib. to Nat. Hist, of Kerguelen Island, by J. H. Kidder, vol. iu 

 p. 74, 1876. 



Tasmania ; 7 fathoms. 



Gorgonocephalus chilensis, Lym. 



Astrophyton chilense, Phil., Wieg. Arcliiv, p. 268, 18.58. • 



Chili. 



Gorgonoce'phalus mucronatus, Lym. 



Astrophyton mucronatum, Lym., Bull. Mus. Comp. Zool., vol. i., part 10, p. 348, 1869. 

 Florida; 120 to 125 fathoms. 



Euryale. 

 Euryale, Lmk., Hist. Anim. sans Vert., vol. ii., 1816. 



Disk re-enteringly curved in the interbrachial spaces, and, together with the arms, 

 covered by thick skin. Arms pretty wide at their base and branching by a series of 

 numerous forks having between them shafts which grow suddenly shorter towards the 

 extremities.^ Eadial shields long, bar-like, and in one piece, and extending nearly to 

 centre of disk, so as to form more or less elevated radiating ribs. Entire interbrachial 

 space below covered by stout plates soldered together. A vertical row of stout teeth, like 

 those of Ophiurans, but no mouth papillee, nor tooth papillae. No proper arm spines, but 

 the outer branches have peg-like tentacle scales which are continued nearly to the 

 base of the arm. There are small, simple under arm plates similar to those among 

 Oj^hiurans. Side arm plates at end of arms like long, free flaps, bearing hooks (tentacle 

 scales) : further in they are small and cling close to the arm, and rise scarcely above its 

 under surface. Upper arm plates represented by a double line of small pieces, which 

 support two large spines standing on the upper surface of the arm. Two genital opening 

 at outer corners of each interbrachial space. 



A section of a Euryale (PL XLV. fig. 6) shows the aspect of a non-gravid individual, 

 the pouches of whose digestive cavity are nearly empty, instead of being stufled with the 

 clotted substance mentioned under Gorgonocephalus. Above is seen the digestive cavity, 

 which, on the right and left, passes into pouches ; and partitions, forming similar pouches, 

 may be seen on the farther side of the centre. Above the lateral pouches are the radial 

 shields (1,1) cut through. On the extreme right and left are greatly dilated genital 

 openings («,o), which lead directly into the body cavity ; and this, passing under and 

 outside the digestive cavity, is connected, about the mouth, by the perihsemal canal, a 

 cross cut of which appears at <^ A section of the disk skin, above the body cavity, 

 (fig. 7) exhibited a uniform, tough, slightly fibrous composition, with a thin lining 



' For the mode of branching, see T. Lyman, Proc. Bust. Sue. Kat. Hist., vol. .\i.\., March 1877. 



