198 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



regular, transverse, oblique rows at sides of ray and median interradial 

 area; no definite arrangement of paxillae in the center of disk. Paxillae 

 largest at base of ray and interradial areas, decreasing conspicuously in 

 size toward the center of disk and tip of ray. Column of paxilla slightly 

 higher than width of base, constricted at the summit. The largest bear 10 

 short spinelets constricted at the base and greatly enlarged into a finely 

 serrated sphere at the tip. Each paxilla bears 1 or 2 central spinelets and 

 up to 9 in the peripheral series ; smaller paxillae carry only 4 or 5 periph- 

 eral spinelets, not reduced in size. 



Abactinal plates are small, compact along the midradial line and cen- 

 ter of the disk where papulae are lacking. The plates of the papular areas 

 in general are circular with 4 to 6 lobes, irregular in length, thickness, and 

 distribution. Plates of the papular areas are arranged in regular transverse 

 oblique rows, parallel with the interradial line. There are 6, often 5, and 

 occasionally 4 papulae around each plate, emerging from between the 

 lobes by which the plates usually touch. Plates along the median area of 

 the ray are even less regular, often without lobes ; they are slightly small- 

 er, and the papulae are absent from a median strip about three plates 

 wide. Toward the center of the disk the plates rapidly decrease in size, 

 they become more crowded, and lobes if present are inconspicuous and of 

 irregular occurrence. 



Superomarginal plates 18 from median interradial line to tip of ray, 

 forming an arched bevel to border the abactinal area. They are rectangu- 

 lar, with a convex surface, about three times wider than long, largest 

 interradially and gradually decreasing in size distally. Marginal plates 

 of both series are separated transversely by deep, narrow, fasciolar 

 grooves, and a deep longitudinal groove separates the supero- from the 

 inferomarginal plates. Superomarginal plates covered with numerous, 

 close-set, finely serrated capitate spinelets. The marginal spinelets are 

 slightly smaller and more delicate. The heavier, coarse, median spinelets 

 are arranged in 3 transverse rows on the interradial marginals, then 2 

 rows on median plates, and a single row on the most distal plates. They 

 are about the same size as the actinal, paxillar spinelets. 



Terminal plate large, conspicuous, its length equal to the width of 

 four adjoining superomarginal plates; abactinal surface broadly convex; 

 proximal margin with a broad concave notch ; distal margin blunt, with 

 a deep furrow groove. Distal half naked, proximal half covered with 

 capitate spinelets, which diminish gradually in size distally, where they 

 are only one third the size of those on the proximal margin. 



