REPORT ON THE ASTEROIDEA. 



427 



/S. Bathymetrical range : 100 to 140 fathoms. The genus is thus confined to the 

 Littoral zone. 



<y. Nature of the Sea-bottom: Pholidaster squamatus is found on Green mud ; Pholi- 

 daster distinct us on Blue mud. 



Chorological Syno2isis of the Species. 



1. Pholidaster squamatus, n. sp. (PI. LXVII. figs. 5 and 6 ; PI. LXVIII. figs. 5 and 6). 



Rays five. R = 75 mm. ; r = 8 mm. R<9 5 r. Breadth of a ray near the base, 8 to 

 8*5 mm. 



Rays elongate, semicylindrical, rounded abactinally, flattened actinally, tapering from 

 the base to the extremity. Interbrachial arcs acute. Disk very slightly higher than the 

 base of the rays, faintly convex. 



All the plates on the abactinal surface, excepting the median radial series and some 

 of the primary apical plates on the disk are masked by large skin-covered scales, each 

 distinct and appressed to the ray, lookiug at first sight more like well-defined plates than 

 scales. The centre of the disk is occupied by a circular dorso-central plate, the surface 

 of which is smooth and covered with thin skin, aud the margin surrounded with a compact 

 ring of skin-covered scales. External to this may be seen in some examples five small 

 under-basal plates, which are circular, smooth, and surrounded by a ring of scales like the 

 dorso-central plate. In other examples, however, the under-basal plates are masked and 

 the space between the dorso-central and the primary radials is occupied by scales, as in 

 PI. LXVII. fig. 5, which look like polygonal close-fitting plates. The primary radial 

 plates are large, irregularly oval transversely, smooth, and surrounded by a ring of scales. 

 The succeeding median radial plates are all broader than long and are separated from 

 one another by a straight row of five subquadrangular scales, the outer one at each end 

 of the series being rather larger than the three centra) ones, attached to the outer margin 

 of the plate, the free end of the scale being directed outward. The breadth of the median 

 radial series of plates is one third of the breadth of the ray. On each side of the median 

 radial series is a series of small plates, which bear a single large scale, but sometimes a 

 large one and a small one are present, by which they are entirely masked. External to 

 these is a series of large marginal plates, much broader than long, which bear two sub- 



