378 s. goto: 



" The marginal plates form a -well-roimdecl lateral wall, the cm-vatm-e of 

 the inferior series being slightly fuller or more tumid tlian tliat of the 

 superior series. The superomarginal j)lates are thii-ty-two in number from 

 the median inteiTadial line to the extremity. The height of the plates in 

 proportion to their length is gi'eatest in the interbracliial arc ; and the 

 breadth of the marginal border as seen from above is also rather broader in 

 the interbrachial arc. Mid^^'ay along the ra^^ it is nearly equal to the 

 breadth of the intermediate imxiUar area. The superomarginal plates bear no 

 spines, but are covered with a low, tiamcate, closely x^acked polygonal granu- 

 lation. The granules are largest near the summit of the arc of cm-vatm-e ; 

 and the plates are shghtl}- tumid along their median line, transverse to the 

 axis of the ray. The odd terminal plate is of a roimded shield-shape, and 

 subtubercular in appearance. 



" The inferomarginal j)lates correspond to the superior series ; their 

 covering, however, is distinctly squamiform, except at the extreme margins, 

 where the gi-anules at the outer end of the plate j)artake of the character of 

 those of the adjacent superomarginal plates, whilst those at the inner end 

 form a transition to the granules of the actinal intermediate plates. Some 

 of the squamules on each plate are more elongate and si3iniform than the 

 rest, but the definite line of small pointed adpressed spines noticed in 

 Pseudarchaster tesseUahis and Pseudar chaster discus is wanting in the present 

 si^ecies. 



" The armatm-e of the adambulacral i^lates consists of a fm-row series 

 of five spines, their base line fomiing an acute angle into the fm-row. They 

 are moderately long and tliickened towards the extremity, which, in the 

 case of the middle spine, is more or less flattened in the direction transverse 

 to the axis of the ray, but in the other spines in the direction of the 

 margin of the plate to wliich they are attached. External to the fm-row 

 series is a line of three shoi-t papiUiform spinelets x)arallel to the fm-row, 

 rather wide apart, and of which the two outside spines often appear as if 

 they belonged to the fmTOW series. Behind these is a second and similar 

 longitudinal series of tlu-ee spines, the middle one being often longer tlian 

 the others; and these are followed by tlu*ee or fom* smaller papillae, com- 



