On new Species (>/'Opluocoma. 39 



IV. — Descriptions of two new Species of Ophiocoma. By 

 Edgar A. Smith, F.Z.S., Senior Assistant in the Zoolo- 

 gical Department, British Museum. 



These two interesting forms of Ophiuridoe were collected by 

 Mr. George Gulliver at the island of Rodriguez, together 

 with Ophiocoma erinaceus, Miiller and Troschel, and Ophio- 

 mastix venosa, Peters. 



Ophiocoma variegata^ n. sp. 



Disk circular, finely granulated above and beneath ; oral 

 shields rather longer than broad, faintly octangular, sides recti- 

 linear ; adoral shields narrow, extending along the lateral 

 margins of the oral shields ; mouth-papillge three on each 

 side of each oral angle, the outermost being the largest and 

 squarish ; and above the teeth at the apex of the angle is an 

 irregular cluster of about twelve smaller papillae ; teeth four, 

 strong, with curved ends. Arms about four times as long as 

 the diameter of the disk, rather stout ; upper plates trans- 

 versely narrowly oval, with the outer margin faintly angulated 

 in the middle, about twice as broad as long ; lower plates 

 squarish, the aboral angles rounded, the side margins exca- 

 vated ; arm-spines four, subequal, the uppermost a trifle the 

 shortest and stout, and the lowest but one a little the longest, 

 about as long as the width of the dorsal arm-plates (the tenth) ; 

 ambulacral scales two in number to the extremity of the arms, 

 short and compressed. 



Colour (of specimen in alcohol) : — disk above and beneath 

 uniformly purplish brown ; upper arm-plates dirty brown, at 

 intervals varied with three or four contiguous pale ones, which 

 are marked with the dark outline of a subquadrate figure, 

 particularly observable towards the ends of the arms ; lower 

 arm-plates pale, blotched, particularly towards the extremity 

 of the rays, with dirty brown ; arm-spines of a uniform tint, 

 but paler than the upper arm-plates ; oral shields pale, mottled 

 with dirty brown. 



Diameter of disk 28 millims., length of arm 105, diameter 

 of widest dorsal arm- plates 4, 



The nearest ally of this species is 0. scolopendrina^ Lamarck, 

 which differs from it in coloration, the form of the arm-shield, 

 oral shields, and the brachial spines. The dark outline which 

 encloses a somewhat quadrate light-coloured space, on the pale 

 superior arm-plates, is very characteristic, as also is the dirty- 

 brownish mottling on the oral shields and lower arm-plates. 



