256 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



large tubulate abactinal plates, fewer than in Mediaster, and in hav- 

 ing large triangular papular areas on the disk, with upward of 10 or 

 even more (as high as 18 in Nectria ocellata) papulae. 



M EDI ASTER ORNATUS Fisher. 



Mediaster oniatus Fishek, 1906, p. 1046, pi. 16, figs. 3, 3a-& ; pi. 20, figs. 1 

 and 2.— KoEHLEK, 1909, p. 78, pi. 10, fig. 4 (Arabian Sea). 



Azotes on PhiUppine sjjeclmens. — The 3 examples, very nearly of a 

 size, are all larger than the Hawaiian specimens and present several 

 minor points of difference. The ray is a trifle slenderer at the tip, 

 the abactinal plates more compact, but not necessarily larger, the 

 actinal intermediate granules a little smaller, more depressed, and 

 the sutures between the plates not so conspicuous or deep. The fur- 

 row spines are 6 or 7, but occasionally 5, and the series of subambu- 

 lacral spines is not quite so prominent. In Hawaiian specimens the 

 furrow spines vary from 6 to 8, and very rarely a shorter ninth spine 

 is present. But the Hawaiian examples are rather variable in the 

 form of the granules, compactness of plates, and in the number of 

 spines and granules. A character not brought out in the original 

 descripti,on and one which is exhibited by most species of the genus 

 is the presence, on the outer attenuate part of the ray, of an enlarged 

 club-shaped subambulacral, much longer than the furrow spines and 

 situated in the middle of the inner subambulacral series, the other 

 members of which are shorter than the furrow spines. 



The internal supplementary ossicles of the abactinal plates are 

 slender and overlap the plates for a third of their diameter. There is 

 no dilFerence between the Philippine and Hawaiian specimens in this 

 regard. The Philippine example dissected has the gonads in a series 

 lof 10 tufts extending from the interbrachial septum (at about mid- 

 way between center and margin) along the sixth longitudinal series 

 of plates from the midradial, reaching to the fifth superomarginal. 

 In a medium-sized (not the largest) Plawaiian specimen there are 5 

 or 6 tufts, reaching the fourth superomarginal. The series in the 

 Philippine example is longer than in any species of the genus. 31. 

 aequalis constantly has only 3 tufts. R = 78 mm., r=33 mm., R= 

 2.33 r; another specimen, R=78 mm., r=31 mm. 



Type-locality. — Station 4022, east coast of Kauai Island, Hawaiian 

 Islands, 399-374 fathoms, coral sand, foraminifera ; bottom tempera- 

 ture 41° F. 



Distribution. — Hawaiian Islands, Philippine Islands, and the 

 Arabian Sea, 286 to 492 fathoms. 



Specimens examined. — Three from the following stations: Station 

 5450, Lagonoy Gulf, east coast Luzon, 408 fathoms, green mud, coral, 

 bottom temperature 42.3° ; 1 specimen. Station 54()7, same locality, 

 480 fathoms; 2 specimens. 



