REPORT ON THE ASTEROIDEA. 115 



3. Pseudar chaster intermedins, n. sp. (PI. XIX. figs. 3 and 4 ; PI. XLII. figs. 5 and 6). 



Pays five. E = 35 mm. ; r = 11 mm. R > 3 r. 



Rays moderately long, tapering continuously from the base to a finely pointed 

 extremity; breadth midway between the centre of the disk and the extremity, G - 5 mm. 

 Interbrachial arcs well-rounded. 



The paxillse of the abactinal area are rather small, subcircular, and closely placed, 

 surmounted by ten to fifteen short, truncate, polygonal spinelets, two or three central ones 

 usually larger than the rest, but these are irregular in disposition, and smaller ones may 

 appear at the periphery and increase the difficulty of enumerating the spinelets. The 

 paxillas are disposed in regular longitudinal lines along the ray, a median radial series being 

 clearly distinguishable and slightly larger than the others. The primary embryonic plates 

 are discernible, though not much larger than the neighbouring plates external to them. 

 The paxilke diminish slightly in size as they approach the margin and proceed along the 

 ray. A considerable number of smaller paxillae occupy the area within the circle of the 

 primary basal plates, and the dorso-central plate is small and inconspicuous. The madre- 

 poriform body is small and sunken, and lies external to its adjacent primary basal plate. 



The marginal plates form a well-rounded lateral wall, the curvature of the inferior 

 series being slightly fuller or more tumid than that of the superior series. The supero- 

 marginal plates are thirty -two in number from the median interradial line to the extremity. 

 The height of the plates in proportion to their length is greatest in the interbrachial 

 arc ; and the breadth of the marginal border as seen from above is also rather broader 

 in the interbrachial arc. Midway along the ray it is nearly equal to the breadth of 

 the intermediate paxillar area. The supero-marginal plates bear no spines, but are covered 

 with a low, truncate, closely packed polygonal granulation. The granules are largest 

 near the summit of the arc of curvature ; and the plates are slightly tumid along their 

 median line, transverse to the axis of the ray. The odd terminal plate is of a rounded 

 shield-shape, and subtubercular in appearance. 



The infero-marginal plates correspond to the superior series ; their covering, how- 

 ever, is distinctly squamiform, except at the extreme margins, where the granules at the 

 outer end of the plate partake of the character of those of the adjacent supero-marginal 

 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 

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

 Pseudarchaster tessellatus and Pseudar chaster discus is wanting in the present species. 



The armature of the adambulacral plates consists of a furrow series of five spines, 

 their base line forming an acute angle into the furrow. They are moderately long and 

 thickened towards the extremity, wdiich, 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 which they are attached. External to the furrow 



