192 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



paxillae is found scattered rather widely over the disk, where it is 

 of inconspicuous size. On the ray they are larger and more numer- 

 ous than on the disk, and more numerous in the larger of the 2 

 specimens, being found on the lateral as well as on the median por- 

 tions of the area. The furrow spines vary from 7 to 9, and the sub- 

 ambulacral spine is prominent and curved slightl3\ The plates of 

 the outer third or two-fifths of ra}^ hav^^a small subambulacral 

 spinule between the principal spine and the furrow margin, and the 

 first 2 or 3 plates may also have a similar spinule (but sometimes 

 placed external to the large one). On the rest of the ray a slightly 

 enlarged subambulacral spinelet usually stands aborad to the large 

 spine. A number of spinelets stand merely on the edge of the plate 

 and form a cordon spaced from the base of the large spine. There 

 are 13 to 14, rarely 12 or 15, adambulacrals to the first 10 inferomar- 

 ginals. The actinal intermediate plates are covered w^th spaced, 

 pointed, slightly swollen spinelets, with usually an enlarged central 

 spine. I do not think the presence or absence of the enlarged spine 

 is of much importance for classificatory purposes. 



The specimen from station 5111 has 2 small pectinate pedicellariae — 

 almost rudimentary — in one interradial area ; otherwise pedicellariae 

 are absent. 



The papularium is flat and distally strongly two-lobed. I am 

 unable to trace a tendon from the dorsal muscles, but the tenth and 

 eleventh ambulacral ossicles are slightly higher than the preceding. 

 It is probable that a very rudimentary tendon is attached to their 

 outer ends. 



Type.— Cat. No. 21157, U.S.N.M. 



Type-locality. — Station 3865. Pailolo Channel between Molokai 

 and Maui, Hawaiian Islands, 256-283 fathoms, fine volcanic sand 

 and rocks; bottom temperature 44.8° F. 



Distribution. — Hawaiian Islands, Philippine Islands, Indian Ocean 

 south of Ceylon; bathymetrical range, 256 to 684 fathoms. 



Specimens examined. — Two : 



Station 5111, Balayan Bay, Luzon, 236 fathoms. 



Station 5445, north coast of Samar, 383 fathoms, green mud, sand ; 

 bottom temperature 44.3° F. 



CHEIRASTER NIASICUS Ludwig. 



Plate 47, fig. 2 ; plate 54, figs. 4, 4fl. 



Cheirastcr niasicus Ludwig, 1910, p. 456. 



Diagnosis. — Differing from Cheiraster inops in having pectinate 

 pedicellariae on the actinal intermediate plates and usually also fas- 

 ciculate pedicellariae on the inferomarginals, as well as more numer- 

 ous abactinal spines on the disk. Abactinal spines variable in num- 

 ber, but scattered all over disk and rays ; superomarginals encroach- 



