STARFISHES OF THE PHILIPPINE SEAS. 445 



tions of ray are united into transverse series independent of each 

 other, or the lobes may touch, depending somewhat upon the amount 

 of inflation of the integument. In the radial region, the plates are 

 frequently independent, and small as well as medium-sized plates 

 are present in the large incomplete meshes of the skeleton. These 

 growing plates are oval, elliptical, or incipiently 3-lobed. 



In the small specimen the inferomarginals define the ambitus, but 

 in the type the}^ retreat slightly onto the ventral surface in the inter- 

 brachium. Inferomarginals 48, compressed as in S. paxillatus with 

 proximally a low fan-shaped pedicel, the width of which diminishes 

 distad. Proximally, the spiniferous margin is about twice the height 

 and bears about 30 spinelets, small at the outer end and increasing 

 in length toward the inner, where 5 or 6 spinelets are 6 or 8 times 

 the length of the outermost, sharp, and invested in pulpy membrane. 

 On the outer part of the ray the pedicels become narrower and the 

 larger spinelets occupy the greater part of the free margin, the small 

 spinelets becoming greatly reduced in number, usually to a few at 

 the upper or outer end. As compared with paxillatus the inner spine- 

 lets of the inferomarginals are decidedly larger and are more as they 

 are in S. horealls, but the spinelets are more numerous and the pedicels 

 lower. In horealis the lateral spines are very conspicuous on the 

 distal marginals. 



Superomarginals very small, with 8 or 10 spinelets, and situated 

 usually above an interspace between 2 inferomarginals. 



Actinal interradial areas large, containing 6 chevrons of plates (4 

 in small specimen), bearing each 5 to 8 pointed spines, heavily in- 

 vested in membrane. These fascicles of spines are well spaced 

 (usually about the length of the spines apart). Two series of inter- 

 mediate plates extend to the eighth inferomarginal and a single 

 series (each plate with usually only 1 spine) extends nearly to the 

 tip of ray. 



Furrow spines, 5 or 6, the median slightly the longest, all united 

 by web for two-thirds their length, the membrane often forming a 

 spatulate pad at the tip of each spine. The spines are tapering, 

 pointed, and rather long, being 1^ to 1^^ the length of base line of 

 comb, and long enough when erect to extend well above surface of 

 plate. Subambulacral spines usually 5 to 7, tapering, pointed, basally 

 webbed and heavily invested in membrane, about equal in length to 

 the furrow spines, but much heavier. The inner spine is shorter 

 than the other 4 or 5 and situated aborad of the transverse line made 

 by the series; or 2 spines form a longitudinal series just back of the 

 furrow series, and 3 or 4 others a transverse series across plate op- 

 posite the interspace between first 2 spines. The subambulacrals are 

 joined by a slight web to the furrow fan. 



