1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 273 



in the much longer and more numerous furrow-spines ; in the larger 

 and more evenly spined dorsal pseudopaxilloe ; in the much smaller 

 and more spinulated ventral areas ; and in the shorter and broader jaw- 

 plates and shorter mouth-spines. 



SOLASTER BENEDICTI, new species. 



Eays usually nine, moderately long, well-rounded, tapering rapidly 

 to the narrow acute tip; rather high at base; in length about equal 

 to the diameter of the disk ; the lesser to the greater radii are as 1 to 

 2.75, Greatest diameter of the largest type specimen, 220 mm.; lesser 

 radius 38-42 mm.; greater radius, 105-115 mm.; breadth of arms at 

 base, 25 mm. ; height of arms at base, 15 mm. ; diameter of dorsal paxill^e, 

 about 5 mm. ; diameter of madreporic plate, 3 mm. ; distance from the 

 center of the madreporic plate to anus, 11 mm.; length of the crests of 

 the marginal plates transversely, 3 mm.; height, including spinules, 

 about 2 mm. Jaws broad, truncated, with four subequal oral spines 

 and numerous small lateral spines. 



The disk is thick, swollen, usually convex. The whole dorsal and 

 lateral surfaces of the disk and arms are covered with small, well sepa- 

 rated, conical pseudopaxillje which bear a small group of tapering, 

 acute, divergent spinules. The pseudopaxilhe on the central region 

 of the disk are larger than elsewhere and bear about 5 to 7 spinules, 

 of which 1 is central and sometimes longer than the others. 



On the sides and towards the ends of the arms the pseudopaxillie 

 decrease regularly in size until they bear but one or two small spinules 

 near the tips of the arms. On the sides of the arms they are arranged 

 in quincunx and form regular oblique rows. On the dorsal surface 

 they are arranged regularly, but do not form very distinct rows. The 

 papuhe are rather small and mostly occur singly in each interspace 

 between the plates, which are rather firm and form a closely reticulated 

 skeleton. The madreporic plate is small, inconspicuous, partially con- 

 cealed by several special pseudopaxilhie larger than the rest; it is 

 situated decidedly nearer to the center than to the margin. Anal open- 

 ing conspicuous, nearly central. The upper marginal plates are very 

 small and bear pseudopaxillpe similar to, and only slightly larger than, 

 those of the plates above them. Inferior marginal plates much larger, 

 with a prominent, much compressed, transverse crest which bears a 

 row of small conical spinules, of which there are 10 to 12 or more 

 on the plates near the base of the arms, where they mostly form a sin- 

 gle row, but on the distal portion of the arm, where the plates become 

 thicker and more rounded, the spinules are shorter, stouter, and form 

 two rows; the spinules near the lower margin of the plate are the 

 longest; when well preserved these spinules usually taper to an acute 

 tip. In the interradial angles the crests of the marginal plates become 

 very thin, and the spinules are more slender, more numerous, and often 

 form a single regular row. The actinal interradial areas are moderately 

 Proc. X. M. 94 18 



