198 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



the pedicellariae occur on the disk and nearly to tip of ray. Other 

 examples from the same station have only a few abactinal pedicel' 

 lariae, while in still others they may be all but absent. 



Superomarginals with a distinct dorsal surface, the spine being on 

 the lateral face, spaced from the inner edge and in length equal to 

 2 to 3 plates. It is a little longer than in snydeH. Below the prin- 

 cipal inferomarginal spine, which equals in length 2 to 3 plates, is a 

 transverse row of 2 secondary spines, the median often over half as 

 long as the lateral spine; or there may be 3 or 4 spaced secondary 

 spines forming an irregular group. The inferomarginal armature 

 is more prominent than in snyderi^ where the principal spine scarcely 

 ever equals 2 plates in length. At the base of the ray there is some 

 irregularity in the number and position of the secondary spines. 



Furrow spines long, slightly curved, commonly 9 or 10, sometimes 

 11, distally. The ends are usually blunt or truncate and slightly 

 flattened. The subambulacral spine is prominent and often slightly 

 curved and equal to 2 plates in length. On the outer part of ray a 

 second smaller spine is present between the main spine and the f uitow 

 margin. As many as 10 to 15 spinelets stand on the edges of the plate 

 and between the subambulacral spine and outer edge of plate. Two 

 or 3 are conspicuously larger than the others, especially 1 near or 

 on the aboral margin, which far along the ray moves inward and be- 

 comes the accessory spinule. The first 2 or 3 plates usually have 1 

 or 2 accessory subambulacral spines of conspicuous size, but beyond 

 this point there is but 1 spine and the 2 or 3 enlarged spinelets spoken 

 of above, until the outer part of the ray is reached when a second 

 is regularly present. 



Marginal mouth spines 8 to 10, the inner 2 broad, truncate, spatu- 

 late. There is one conspicuous suboral spine near the margin and 

 15 to 20 suboral spinelets, those near the inner end the longest but all 

 conspicuously shorter than the spine. 



Pedicellariae are present: (1) Sparingly on the abactinal surface. 



(2) A few between the superomarginal and inferomarginal plates. 



(3) Subcircular fasciculate pedicellariae near the inner edge of the 

 inferomarginals, often with 1 or 2 of the spines standing on an ad- 

 jacent adambulacral plate. There are usually 6 to 8 sharp, taper- 

 ing jaws to each, and they extend upward of three-fourths the length 

 of the ray, being absent usually from the first 2 plates. There are 

 1 or 2 to a plate and they occupy the same position as do the pedi- 

 cellariae in Pectinaatev mimiais, except that here the jaws are slen- 

 derer and sharp. (4) Upward of 12 prominent pectinate pedicel- 

 lariae to each actinal interradial area. In the largest specimens 

 the actinal plates extend to the fourth inferomarginal (sometimes 

 the third) and bear in addition to the pedicellariae numerous spaced 

 spinelets and usually an enlarged spinule. The latter is not at all 



