ASTEEOIDEA OP H.M.S. ' CHALLENGER ' EXPEDITION. 253 



subtubercular prominence ; the whole surface covered with small 

 robust papilliform spinelets, forming two or three lineal series on 

 each plate. These spinelets increase in length towards the inner 

 extremity", the innermost ones not being greatly longer or more 

 prominent than the rest. 



The paxillsB of the dorsal area are large and uniform, and are 

 arranged in regular transverse lines which extend up to the 

 median line of the ray. The paxillse have a large tabular surface 

 on which are placed twelve to fifteen short papilliform spinelets, 

 and the periphery is surrounded by about an equal number of 

 similar spinelets. In the centre of the disk the paxillse are smaller, 

 and are very compactly placed. There is no trace of any anal 

 puncture, and no protuberance in the centre of the disk. 



The madreporiform body is very small, and is situated at about 

 one third of the distance from the margin to the centre, and some- 

 times rather further away from the margin even than this. In 

 some specimens there is a faint depression along the median line 

 of a ray ; and in large examples a similar slight sulcus occurs on 

 the outer portion of the median interbrachial line. 



Colour, in alcohol, a light purplish shade, of which only a trace 

 remains in some specimens, the rest being almost ashy white. 

 Station. Port Jackson. 6-15 fms. 



Station 161. Off entrance of Port Philip. Depth 38 fms. ; 

 sand. 



Station 162. Off East Moncceur Island, Bass Strait. Depth 

 38-40 fms. ; sand. 



ASTKOPECTEN ACANTHIEER, U. sp. 



E-aysfive. E>6'5r; E=90 millim.,r=14millim. Eays elon- 

 gate and tapering ; disk very small. Breadth of a ray at the 

 base 14"5 millim. ; interbrachial angles acute. Supero-marginal 

 plates rather higher than broad, 43 in number from the inter- 

 brachial angle to the tip. Each plate bears on the outer dorsal 

 margin (or rounding that falls in the marginal contour) a single, 

 small, delicate, conical, and sharply pointed spine. The series is 

 continuous throughout the ray ; and the two innermost spinelets 

 are rather more robust than the others. 



Infero-marginal plates broader than high, and do not extend 

 beyond the superior series. Marginal spines three, close together 

 in transverse series : the outermost, or marginal spine proper, 

 is long, delicate, cylindrical, tapering to a sharp point, and slightly 



