£ 



THE OPHIURIDiE. 



145 



# 



4= 



Var. h (Plate VIII. Figs. 6-8) resembles the typical form very closely. 

 The ventral plates have the outer edge more rounded, and there is a more 

 distinct keel; the radial shields are narrower. The most important differ- 

 ence is. however, that it has four, on the inner joints five, arm-spines ; the 

 upper one is the shortest, about as long as half an arm-joint ; they then 

 become gradually longer downwards, the lowest being the longest, a little 

 longer than a joint. The mouth papilla) are more or less pointed. 



Vak. c (Plate IX. Figs. 1, 2) differs much more from the typical species, 

 and should perhaps be regarded as a separate species. The arms are*c. 15 

 times as long as the diameter of the disk (6 mm.). The outer mouth papilla 

 is long and pointed ; the mouth shield has not the common form, but there 

 is a rounded angle within, and the outer part is not so" much restricted. 

 The ventral plates are more elongated, longer than broad ; outer edge usu- 

 ally a little re-enteringly curved. The keel rather indistinct. The dorsal 

 plates are more round than common; the radial shields very narrow, sepa- 

 rated by some few scales. The scales of the disk resemble those of var, a, 

 but are longer and narrower ; the primary plates distinct. In other re- 

 spects it resembles the typical form. (One spechnen only.) 



In the typical form and var, h the spines may have a dark brown tint on 

 the middle, and the mouth then has the same color. 



Several specimens from Stations 3384, 458 f. (typical form); 3393, 

 1020 f. {var, 6); 3394, 511 f. (var, a); 3402, 421 f. {var. c) ; 3419, 772 f. 

 (wr. ^0; 3424, 676 f {var. a). 



m 



27. Ampniura gymnogastra n. sp, 



Plato IX. Figs. 6-8. 



Diixmeter of disk, 9 mm.; widtli of arm close to disk, without spines, 

 1 mm. ; length of arms, about ten times the diameter of the disk. One 

 rather 'long" and stout conical mouth papilla on each side,* besides that 

 on the apex. Mouth shield equally long and broad, almost rhomboidal, 

 outer sides a little re-cnteringly curved, inner sides straight, all the angles 

 rounded, the inner angle more so than in the figure. Side mouth shields 

 sometimes meeting within, sometimes separated, much broader without than 

 within ; they may also be quite triangular. 



« 



* One specimen has two outer paplUie ou oue mouili angle. 



