642 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 43. 



and larger mouth plates. Form pentagonal, with straight sides, 

 produced at the angles into rays only 2 superomarginals in length. 

 Superomarginals narrow, increasing slightly in size up to the tliird, 

 the remaining 2 being smaller; surface bare, except for scattered 

 granules, and several rows near margin. Abactinal plates granulate, 

 a comparatively few of the radial and adradial series being low 

 tabulate; plates hexagonal on radial regions, generally 4-sided 

 interradially, and irregularly hexagonal on center of disk. Adambu- 

 lacral plates longer than wide, or as long as %vide, ^vith a straight- 

 edged furrow comb of 9 or 10 flattened, rather narrow, truncate 

 spines, and spaced from these 2 or 3 subambulacral series of granules, 

 the inner the larger. Mouth plates large with 15 to 17 furrow spines. 

 Abactinal, marginal, and actinal intermediate spatulate pedicel- 

 larise with ''sugar-tongs" jaws. R = 32 mm., r = 22 mm., 11 = 1.45 r. 



Type.— Cat. No. 30553, U.S.N.M. 



Type-locality.— St&tion 5425, Sulu Sea near Cagayanes Island, 495 

 fathoms, gray mud, coral sand. 



ICONASTER PERIERCTUS, new species. 



Differing from /. longimanus in having more elevated, and rough 

 superomarginals; all the abactinal plates perfectly smooth and with 

 a complete series of peripheral granules ; a less compact adambulacral 

 armature with fewer spines and granules. E, = 23 mm., r=10 mm., 

 R = 2.3 r; breadth of ray at inner end of third superomarginals, 6 

 mm., or the length of the first 3 superomarginals measured on 

 ambitus. Superomarginals tabulate, separated by conspicuous 

 grooves, the surface having irregular elevations but no granules nor 

 blister-like minute bosses; beyond the second plate they are united 

 on the median line of ray ; abactinal area sunken, the plates perfectly 

 smooth with a single peripheral series of granules largest on the 

 radial papular areas; peripheral plates tumid, the others shghtly 

 swollen, with a plane surface, but not tabulate; plates of center of 

 disk very conspicuously the largest; inferomarginal plates tumid, the 

 first 3 or 4 perfectly smooth, the remainder with slight roughening; 

 actinal intermediate plates in 3 chevrons, smooth, with a single 

 peripheral series of oblong granules; adambulacral plates small, 

 ^^^der than long with 3 or 4 small, stubby, furrow spinelets and fol- 

 lo-wing these, 2 shorter, compressed, fiat-sided granules, the outer 

 part of the plate being occupied by 4 or 5 small prismatic granules. 



Type.— C&t. No. 30554, U.S.N.M. 



Type-locality. — Station 5166, 4.6 miles southeast of Observation 

 Island, Tawi Tawi Group, Sulu Archipelago, 97 fathoms, coral sand; 

 bottom temperature, 69.4° F. 



The generic position of this species is puzzhng. The dorsal skeleton 

 and the very tumid, roughened, superomarginals would ally it to 



