STARFISHES OF THE PHILIPPINE SEAS. 443 



long as two plates, or a trifle less, slightly tapered, bluntly pointed, 

 and sometimes faintly grooved on the outer side near the tip. 



The actinal intermediate spines (of which the innermost series 

 extends nearly to end of ray) are about two-thirds the length of the 

 subambulacrals on the disk, and subcqual on the ray. On the disk 

 the intermediate spines are in about 3 irregular chevrons, including 

 that adjacent to the subambulacrals. Inferomarginal spines, IT 

 or 18 ; superomarginal spines about 7, the longer 6 to 9 mm. in length. 

 Actinal granulation rather coarse, though the skin magnifies the size 

 of the actinal granules. This granulation is found also on the base 

 of the spines, but not on the shaft. 



Mouth plates narrow, with usually 5 stout flattened spines, fol- 

 lowed by 3 short spinelets, just back of which is a prominent 

 suboral spine. 



Madreporic bodies, 3 to 5. 



Type.— Cat. No. 37027, U.S.N.M. 



Type-locality. — Station 5149, off Sirun Island, Sulu Archipelago, 

 vicinity of Siasi, 10 fathoms, coral, shells; 2 specimens. 



Remarks. — The differences between this form and A. mauritiensis 

 and A. planci can be best appreciated if put in synoptical form. 



c\ Adambulacral spines 3 to 5 ordinarily conspicuously longer than their own 

 plate; spines at least of abactinal surface obviously granulated usually 

 for nearly their whole length ; abactinal pedicellariae with long, slender 

 jaws. 

 &\ Abactinal spines long, acicular, borne on high columns or pedicels belong- 

 ing to the cruciform and rather widely spaced plates ; spines of disk, 

 including pedicels, one-third to one-fourth length of ray, measured 

 along side; actinal spines with a fine granulation, or with a large part 

 of the spine nearly smooth ; subambulacral spine equal to about 3 adam- 

 bulacral plates in length, occasionally 3.5 A. planet. 



b". Abactinal spines distinctly short, those of disk (including pedicel) not 

 exceeding, and usually not attaining, one-sixth the length of ray, meas- 

 ured alongside; actinal spines with a course granulation covering greater 

 part of spine, at least on one side; subambulacral spine less than 3 



adambulacral plates in length A. mauritiensis. 



a\ Adambulacral spines 2 or 3, occasionally 1, not longer than their plate; 

 abactinal spines of disk usually smooth for most of their length, with a 

 three-edged tip, and usually less than one-twelfth the length of ray meas- 

 ured along side; abactinal pedicellariae with short, thick jaws; nctinal 

 spines smooth for the gi-eater part of their length ; subambulacral spines 

 equal to 2 adambulacral plates in length A. brevispinus. 



As compared with planet the disk spinelets of brevispinus are much 

 more numerous, owing to the closer meshed skeleton, and are insignifi- 

 cant in size. 



A. ellisii Gray is not well known. It is described by Perrier as 

 having the spines disposed very nearly as in planci, but completely 

 devoid of granules. The pedicellariae are very short. The rays are 

 either 19 or 15, madreporic bodies 7, and the adambulacral furrow 



