114- BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



series of short pointed spmules just adorally to the series of lateral 

 spines. 



Terminal plate small, rather oblong, v."ith a small notch on the 

 proximal end and a tuft of 5 or 6 small spines on the distal end. 

 Surface covered with small lanceolate squamae. 



Actinal interradial areas small, owing to the breadth of infero- 

 marginals. Intermediate plates exending in a single series to twenty- 

 second to twent3^-fourth inferomarginal or two-thirds the length of 

 ray, but beyond the middle they are very small. A second series of 

 small plates reaches the sixth or seventh inferomarginal. In a trans- 

 verse series between the first adambulacrai and first inferomarginal 

 are 5 or 6 small plates. The plates are spaced and bear paxilliform 

 groups of 8 to 12 papilliform spinelets, and a few plates in the inter- 

 radial region bear also a central tapering sharp spine 2 or 3 times as 

 long as the spinelets. 



Adambulacrai plates slightly wider than long, with wide sutures 

 between. Furrovr margin angular, bearing a comb of 6 or 7 long 

 slender compressed round- or squarish-tipped spines, the central 2 or 

 3 slightly the longest and with edge to furrow, the laterals with flat 

 side thereto. The longest spines, at base of ray, equal 1.5 adambulacrai 

 plates in length or 1.3 inferomarginals, counting the intervening 

 sutures in each case. Subambulacral spines proximallj^ about 6, un- 

 equal, slender, tapering and swollen by membrane, shorter than the 

 furrow spines and arranged in usually a single irregular series. 

 Farther along ra}' the number increases to about 10 short, papilli- 

 form spinelets, in 2 series. On the outer part of ray they are no 

 longer than the inferomarginal spinelets, but, of course, slenderer. 

 The first plate is compressed, but still with a furrow comb of 6, and 

 upward of 15 subambulacrals. 



Mouth plates prominent actinally and with the typical Persepho- 

 naster type of armature. First there is a pair of stout, long, lanceo- 

 late or oblanceolate teeth : betAvcen the base of these and the peristome 

 on either side is an oblique double row, or angular group, of 8 or 10 

 short, flattened, blunt spines, resembling a pectinate or fasciculate- 

 pectinate pedicellaria. These are part of the furrow or marginal 

 spines, and are continued along the side of the plate, adjacent to first 

 tube foot, in a series (on the same level Avith the teeth) ofl 5 or 6 stouter, 

 spatulate spines, forming a palmate group, but smaller in every way 

 than the first adambulacrai furrow series, (^n either side of the 

 broad median suture is a series of about 12 to 15 broad, flat, leaf- 

 like spines, the pair just back of the mouth spines being enlarged, and 

 the outermost of the series smaller and more clavate. Between this 

 series and the marginal, and extending far beyond the latter to the 



