REPORT ON THE ASTEROIDEA. 299 



whilst the outer members of the series are simply truncate papillae or elongate granules. 

 On the margin of the mouth-plate adjacent to the adambulacral plate is a series of six 

 papilliform spinelets or granules similar to the last-mentioned. One or two additional 

 spinelets usually stand on the interspace of the plate formed by the divergence of this and 

 the median series. 



The paxillae of the abactinal area are of two forms, and present a very ornate appear- 

 ance. Those which occupy the radial portions of the disk are hexagonal, tabulate, and 

 well spaced, with a definitely-arranged spinulation ; the covering of the interradial areas, 

 on the other hand, consists of square or rhomboid plates compactly placed and covered 

 with a small uniform miliary granulation similar to that on the supero-marginal plates. 

 The median radial line is occupied by a longitudinal series of transversely elongate hexa- 

 gonal paxilL-e, which are larger than any of the others. Their transverse diameter is 

 2 mm., and the longitudinal measurement (corresponding to the direction of the ray) varies 

 from 1 to 1-5 mm. The margin of the tabulum is occupied by a regularly placed series of 

 twenty-two to twenty-five short, prismatic, sharply truncate spinelets, their truncation 

 being in conformity with the well-defined, regular and sharply-angular hexagonal outline 

 of the paxilla as a whole, which is so regular that these spinelets almost appear as if 

 trimmed into form with a knife. The central portion of the tabulum is occupied by seven 

 to eighteen semiglobular well-spaced granules, which vary in size according to number, 

 but are of uniform size on a given tabulum. When this series of paxillae reaches the 

 base of the ray proper, they lose their tabulate character and appear more like simple 

 hexagonal plates compactly placed, and the marginal series of spinelets lose their 

 prismatic character and become rounded granules similar to those on the surface of 

 the tabulum, and at the same time the latter increase in number. Towards the end of 

 the ray the paxillar plates lose their hexagonal outline and become square, and finally 

 become so small that their serial succession is interrupted by the contact of 

 the two corresponding supero-marginal plates from each side of the ray. The 

 radial series then rapidly aborts, and the extremity of the ray is occupied entirely 

 by the supero-marginal plates. On each side of the median radial line of paxillae, within 

 the area of the disk, are three parallel longitudinal series of similar, but somewhat 

 smaller, hexagonal tabulated paxillae. The outermost two are confined to the area of the 

 disk and terminate at the base of the ray ; the innermost, however, is continued a little 

 further along the ray, nearly to the middle, but the hexagonal form is altogether lost ; and 

 all the plates near the base of the ray and any which proceed along it change the special 

 spinulatiou of the tabulated paxillae for the small miliary granulation similar to that on 

 the supero-marginal plates above noticed. The tabulated paxillae of the three series on 

 each side of the median row are of the same height and character as the latter, and they 

 stand well spaced, so that the star-like prolongations uniting the bases, as well as the 

 papulae, are visible. The row of paxillae next to the median series have their transverse 



