296 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



ginals, becoming reduced to a single series near the end of ray. In 

 acldition the longitudinal borders of plate usually have an additional 

 series, with a few odd granules in the corners or scattered on the 

 lateral face. 



Actinal intermediate plates very numerous, those nearest furrow 

 the largest and with the next or next two parallel series forming 

 fairly regular chevrons, the plates reaching to the twenty-first or 

 twenty-second inferomarginal. The other plates are irregularly 

 arranged. All are closely granulate, the granules flat and immersed 

 in thin membrane. The plates next to adambulacrals bear one or 

 two small, rather delicate, bivalved pedicellariae, whose denticulate 

 jaws are slightly wider than high (the larger ones) or as wide as 

 high (smaller) and fit into slight depressions when open. 



Adambulacral plates proximally long and narrow, very gradually 

 widening on outer half of R, until near tip; beyond the last actinal 

 intermediate plates they are as wide as long. Each plate is angular 

 toward furrow, the angle being sharper deep in furrow than on 

 margin, and is usually adoral to the middle of plate, varying in 

 position between the middle and adoral margin of plate. Furrow 

 spinelets 11 or 12, stout, short, round-tipped or blunt, much flat- 

 tened, those near the angle of margin with edge to furrow, the others 

 with flat side thereto. The aboral spinelet of the series is the broad- 

 est and stoutest, and often the adoral spinelet is similarily enlarged. 

 This spinelet or really granule is most conspicuous near the end of 

 ray, where the furrow angles, meeting medially from the 2 sides, 

 segregate the tube feet as in Nymphaster. The spinelets near either 

 end of the series form an operculum, closing this compartment when 

 the tube feet are withdrawn. 



The spinelets are subequal in length, or the median slightly the 

 shorter. The actinal surface proximally is wide enough for only one 

 longitudinal series of unequal granules, but as the plate widens more 

 are added, until distally the plates have an even granular surface, 

 like that of actinal plates. Proximally most of the plates have a 

 large bivalved denticulate pedicellaria, the jaws much wider than 

 high. This occupies a third or a fourth the length of a plate, the 

 remainder of the first actinal series being filled out by compressed, 

 rounded, granules, usually larger than the other actinal granules. 

 The distalmost of these, on the last 6 to 12 plates, is enlarged and 

 tubercular (although inconspicuous), and this, a goniasterid ten- 

 dency, is carried out, although in a suppressed form. 



Mouth plates small, triangular, Avith a fairly straight furrow 

 margin, bearing 9 or 10 spinelets, similar to those of the furroAV 

 series, but heavier, and increasing rather rapidly in size toward the 

 inner end of plate, where the spines are heavy, compressed, and leaf- 

 like. Back of these is a row of flattened, shorter, truncate, or round- 



