STARFISHES OF THE PHILIPPINE SEAS. 515 



usually evenly rounded except for the central boss, and the ends are 

 spatulate and overlapping. The integument between the ribs is thin 

 and is provided with delicate glassy prickles about half or two- 

 thirds the length of the costal spinelets. These are very numerous 

 on the proximal third of the costal area, gradually thinning out 

 until there are few or none in the last 5 or 6 intercostal spaces. 

 There are about 3 very inconspicuous bands of pedicellariae be- 

 tween the costae and relatively few pedicellariae on the ridge itself. 

 Lateral spines, beginning at about the fourth costa, articulated to a 

 small subtriangular plate, which occurs opposite every other adam- 

 bulacral, but occasionally opposite 2 consecutive plates. The first 

 spine is very short, but they rapidly increase in size, attaining the 

 maximum length (12 or 13 mm.) near the end of the costal region, 

 where they are as long as 5^ consecutive adambulacral plates, and 

 very slender. 



Adambulacral plates proximally wider than long, with a crowded 



i + 1 

 armature, which for the first few plates has the formula — ^ — }- 1 



i + 1 i 



on the fourth or fifth plate becoming — -■ — \-I or ^ + 1 + 1; then to 



= or — . . • At either end of the plate pointing across fur- 

 row is a slender spinelet, usually a little longer than the plate, but 

 if there is an adoral actinal spinule the furrow spinelet is shorter. On 

 the actinal surface are 2 large actinal grooved spines sometimes in a 

 transverse series at middle of plate, or in an oblique series from the 

 inner aboral toward outer adoral corner. The outer spine on the 

 first 10 plates has a flaring truncate tip, ending in numerous points, 

 which is broadest on the most proximal spines, thence decreasing in 

 width as the spine increases in length. The eleventh is usually also 

 truncate, but from here on the spines become pointed. The first 

 spine is equal to 3^ consecutive (short) adambulacrals, the eleventh, 

 4^ or 5 (or the first 7 plates of the ray) ; thence the spines become 

 slenderer and longer, equaling 6^ to 7 consecutive, longer, adam- 

 bulacral plates on the outer part of the costal region. The other 

 actinal spine on the first 2 or 3 plates is slender, pointed, and about 

 three-fourths the length of the very stout outer subambulacral. From 

 the fourth to the twelfth it varies from three-fourths to the length of 

 the outer spine, but is slenderer and frequently has a truncate, slightly 

 flaring tip, though often also a bluntly pointed one. Beyond about 

 the twelfth plate it is two-thirds to four-fifths the length of tlie outer 

 spine, is slenderer than proximally, and always is acicular. A vari- 

 able number of plates have an adoral actinal spine, one and a half to 

 twice the length of the adoral furrow spine. This species has an 

 unusually long secondary actinal spine. Spines covered with pedi- 

 cellariae. 



