STARFISHES OF THE PHILIPPINE SEAS. 49 



The actinal intermediate plates extend to the eighteenth infero- 

 marginal, or somewhat less than half the length of ray, but beyond 

 the fifth inferomarginal there is only a single series, largely ob- 

 scured by membrane. The first double row of plates extends from 

 the first inferomarginal to a mouth plate, and touches also the first 

 2.5 or 3 adambulacrals ; these two series contain 7 and 6 plates, re- 

 spectively. The second double series, with 5 and 4 plates, corre- 

 sponds to part of the third, the fourth, and half the fifth adambu- 

 lacrals, or to the third and fourth only. The third double series has 

 3 plates in each row, and the fourth and fifth double series have 2 

 plates in each row. In addition to the flattened, rather broad, deli- 

 cate spinelets supporting the marginal web, some of the plates have 

 1 or 2 inconspicuous spinelets largely obscured by membrane. 



The adambulacral plates have an angular furrow margin. The 

 facet or side toward the mouth is shorter on the first 10 or 12 plates 

 than the other facet. The first 4 or 5 plates appear as if the furrow 

 margin were oblique, as the short adoral facet is wholly occupied by 

 an enlarged furrow spine. The first plate is compressed. The fur- 

 row spines increase from 6 on the first plate to 9 or 10 far along the 

 ray. Proximally, the adoral spine of the series is much enlarged, 

 the others being graduated in length to the end of the series, the last 

 being short. Beyond the sixth or seventh plate the enlarged spine 

 decreases in relative size, and gradually moves toward the center of 

 the group. The spines form a palmate radiate group, are stout, 

 webbed basally, and have a little knob of tissue on the tip. The first 

 7 or 8 plates have 5 to 8 stubby spinelets on the margin, more or less 

 involved in the web. These become smaller distally, except 1 or 2, 

 which stand on the aboral margin, and become slightly larger and 

 more pointed. The first 6 or 7 plates have a fasciolar groove adja- 

 cent to actinal intermediate plates, but beyond this point the mem- 

 brane is continuous. 



Mouth plates prominent, the combined pair being narrowly trun- 

 cate-elliptical. That part of the margin bordering on the furrow has 



6 or 7 slender spines, followed on the inner end of plates by 2 heavier, 

 longer, blunt spines (shorter than enlarged adambulacral spine). 

 These are placed higher (or nearer the median suture) and merge 

 into a series of 7 or 8 similar spines along the median suture. Six or 



7 other spines of about the same length, but slenderer, form an angu- 

 lar series on surface of plate above the small furrow series, and 

 thence along the border of suture adjacent to first adambulacral. 



Madreporic body convex, with five striae, situated 1.5 times its own 

 diameter from marginal plates. It is as wide as the length of first 2 

 superomarginals. Ampullae single. 



