STARFISHES OF THE PHILIPPINE SEAS. 347 



tubercles are covered with granules, which are variable in size, some- 

 times smaller than at the base, sometimes larger. A few of the 

 tubercles in these specimens may have a blunt spine. The largest 

 primary radial tubercles may terminate in 2 or 3 points. The num- 

 ber of pedicellariae is very variable. They may be very numerous 

 on the dorsal surface or fairly scarce. Their form is also variable; 

 usually the abactinal pedicellariae have slender upright jaws, con- 

 siderably longer than wide. But in examples from Burias Island 

 the pedicellariae are feAv and low, with the jaws as low as or lower 

 than broad. 



The furrow spines vary from 6 to 8. The subambularcral spines 

 are usually 3 in number, much heavier than the furrow^ spines, and 

 grooved or eroded at the tip (as well as down the sides in many 

 large examples). The subambulacral pedicellaria is adoral to the 

 subambulacral spines and between them and the adoral furrow spine. 

 Sometimes this pedicellaria is as long as the median furrow spines, 

 but is ordinarily a little shorter. 



One specimen has 4 normal r&js and 2 short ones. A specimen 

 from Burias Island has lost all the abactinal tubercles, the scars 

 where they were broken off or torn out are very distinct. Other 

 specimens have lost 1 or more tubercles b}^ accident, the wound hav- 

 ing healed. 



The most curious variation is exhibited by a specimen from station 

 5254. which agrees with 2 other examples from that station in all 

 essential respects except the possession of from 1 to 4 superomarginal 

 tubercles on each side of the rays (28 in all). These tubercles are 

 smaller than the dorsal ones. It is possible that this specimen is a 

 hybrid of O. nodosus and 0. alveolatus^ a specimen of the latter 

 having been taken in the same haul. The dorsal tubercles are quite 

 typical of nodosus and not of alveolatus. 



It is worthy of note that a series of very small intermarginal 

 plates (4 to 6 to each interbrachium) is present, but completely hid- 

 den by granules (see Pentaceropsis). 



Distribution. — Eegion of the Indian Ocean, East India Islands 

 (north to Luzon), thence to New Caledonia, in the Pacific. 



Specimens examined. — Thirty-four, from the following localities: 



San Pascual, Burias Island (off Luzon), tide pool on sand, flat, 

 6 specimens. 



Papatag Island, Tawi Tawi Group, Sulu Archipelago, shore, 3 

 specimens. 



Tataan Pass, Simaluc Island, Tawi Tawi Group, shore, 1 specimen. 



Cagayan de Jolo, 1 specimen. 



Pangasinan Island, Jolo, reef, 14 specimens. 



Pandanon Island, between Ccbu and Bohol, coral sand, 1 specimen. 



Eeef off Cebu. 2 specimens. 



