STARFISHES OF THE PHILIPPINE SEAS. 259 



way down the outer face of the tubercle. Scarcely 2 are alike. 

 The spines increase in thickness toward the outer part of furrow, 

 sometimes flaring widely at the tip, and finally 1 increases greatly 

 in size over the rest and becomes a stout conical or clavate tubercle 

 without a trace of the curious wrinkling. The form of these sub- 

 ambulacral spines is difficult to describe, as it varies. They have 

 the appearance of being eaten very unevenly on the outer side by 

 acid. The outer end of the plate is occupied by 4 to 10 prismatic, 

 irregular granules in 1 series on the first few plates, 2 on the rest, 

 or without serial arrangement. I find just 1 plate with a 2-jawed 

 spatulate pedicellaria. 



Mouth plates w^ith slightly curved furrow margin bearing 8 or 9 

 spines variable in form, but similar to the adambulacral spines. 

 They increase in size and become more compressed and broader 

 toward the mouth angle: and the tip. which is usually blunt or 

 truncate, is irregularly pitted and etched out, as described above. 

 Parallel to this is a series of .5 or 6 suboral spines similar to, but 

 larger than, the homologous subambulacral. Six to 12 coarse pris- 

 matic granules occur on the outer part of the plate, mostly on the 

 sutural and lateral margins. 



Madreporic body fairly large, with fine meandering striae, situ- 

 ated one-third of r from the enlarged " central " or apical plate. 



The anatomy could not be worked out beyond the most salient 

 features. Gonads single, on either side of the interbrachial septum, 

 situated about 6 mm. from marginal plates and 4 or 5 from the 

 septum. Polian vesicle long, reaching nearly to marginal plates. 

 No subambulacral ossicles or rudiments. 



Young. — A specimen from station 5348 with R 23 mm. and r 15 

 mm. seems to belong to this species. It differs from the adult in 

 much the same way that a small specimen of clarki diifers from 

 the large type. 



The most conspicuous difference of this young specimen (the 

 gonads are very small) is to be found in the marginal plates. These 

 are relatively heavier, and normal for the genus, and all of them 

 have a dorsal bare spot Avhicli increases in size distad until it occu- 

 pies nearly the entire surface of the plate. The proximal plates 

 are a trifle wider than long, the width increasing gradually up to 

 the eighth, the last 2 plates being smaller. At the same time the 

 length of the plates gradually decreases so that these distal plates 

 are more than twice as wide as long and agree with those of the 

 adult in being larger than the proximal. The abactinal plates have 

 the same character as in the adult but have only 4 or 5 central 

 granules, decreasing to 2 or 3 on the smaller plates, and the 10 or 

 12 marginal granules are slightly larger than the central. The 



