STAEPISHES OF THE PHILIPPINE SEAS. 403 



low parapaxillae, 15 to 20 to a group; single papulae between the 

 abactinal plates ; adambulacral plates small, armature dense, upright, 

 the spinelets grading from the furrow series into those of the actinal 

 intermediate and marginal plates; furrow spines proximally 5 or 

 6, distally 4 or 5, prismatic or four-sided, blunt or truncate, the proxi- 

 mal and distal shorter than the central 3 or 4 ; subambulacral spines 

 in 2 or 3, sometimes 4, series, with 2 or 3, or proximally 4, shorter, 

 less stout spines in each series. General appearance suggestive of a 

 Henricia with closely placed plates. 



Description. — The center of disk and a broad radial streak is paved 

 with close-set, irregularly placed plates bearing a paxilliform group 

 of 15 to 20 short, cylindrical, untapered, round-tipped spinelets either 

 standing erect or diverging. On either side and occupying the dorso- 

 lateral, lateral, and part of actinal surface are 10 longitudinal series 

 of close-set plates which also form regular transverse series, and 

 each bears a roundish, flat-topped, paxilliform, group of 15 to 20 

 short, equal, blunt spinelets, in every way similar to those of the 

 radial areas. As noted above the plates are not arranged in quincunx, 

 but in fours, four of them forming a nearly perfect square. At the 

 corners of the regularly arranged plates as well as on the radial 

 areas and disk are single papulae. Adjacent to the adambulacral 

 plates, and actinal in position are 3 series of close-set, rather irregu- 

 larly elliptical plates, abruptly larger than the dorsolaterals and 

 without papulae between them. The outer 2 are the marginals and 

 the imier series is actinal intermediate. The superomarginals are 

 slightly the largest. 



The marginal and the actinal intermediate plates on the ray, 

 usually, also form pretty definite transverse series and all are cov- 

 ered closely with short, relatively thick, round-tipped spinelets a 

 trifle larger than the dorsolateral spinelets. The spinelets form not 

 very regular 4-sided groups — about 20 to a plate. On the disk 

 several additional series of small actinal intermediate plates are in- 

 terpolated so that the marginals withdraw to about the middle of r, 

 and become smaller as the interradial line is approached so that it is 

 difficult to distinguish them except that the superomarginals are here 

 larger than the dorsolateral plates (here actinal in position). The 

 latter also become smaller on this actinal interradial portion of the 

 disk, and the papulae are lacking proximad of the tenth supero- 

 marginal. 



Between the first superomarginal and second adambulacral of 

 each ray are 6 intermediate plates. Opposite the first adambulacral 

 is a short series joining a couple of unpaired plates so as to form a 

 Y-shaped group. A large plate just back of the mouth plates is 

 embraced by the arms of the Y. Opposite the seventh inferomar- 

 ginal are 2 intermediate olates in a transverse row. Opposite the 



