290 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



light pink, and the arms are banded with pink and white ; one com- 

 ing from a depth of 90 meters was quite decolorized. 



I may recall that I separated 0. fulgens from 0. pulchella, which 

 also occurs in the Albatross collection, on the basis of the armature 

 of the dorsal surface of the disk, the smaller size of the radial shields, 

 the shorter arm spines, and the entirely different coloration. 



The principal variations which I find in the Albatross specimens 

 concern the armature of the dorsal surface of the disk, the dimen- 

 sions of the radial shields, the presence or absence of small granules 

 on the upper arm plates, and the more or less carinate form of the 

 last. In certain specimens, as those from station 5117 (pi. 42, fig. 7), 

 the dorsal surface of the disk shows only rather large rounded gran- 

 ules arranged very uniformly on the plates, and the radial shields are 

 remarkably large. In others, as those from station 5070 (fig. 5) the 

 granules are much less numerous and there are in addition a few 

 large, thick, and short spines, with their tips rounded; the number 

 of these spines is a little greater in the specimens from stations 4935, 

 4948, 5138, 5255, 5395, and especially 5217. In the small specimen 

 from station 5413 and in those from stations 5141 and 5393 (pi. 42, 

 figs. 1, 2) these spines are especially numerous and very long; they 

 have the tip pointed and are provided with fine and closely crowded 

 denticulations ; their presence gives to these specimens a general ap- 

 pearance very different from those which are without spines. Cer- 

 tain individuals from station 5545 are identical with those from 

 station 5393, of which I give a photograph on plate 42 as figure 2, 

 having very large radial shields, and on one of them these radial 

 shields carry two or three spines identical with those on the rest of 

 the dorsal surface of the disk. While the small example from station 

 5414 shows the spines greatly developed, the other is almost entirely 

 without them. The photographs which I give on plate 103 as figure 

 8& and c show the intermediates between club spines and true spines. 



On some individuals the plates which carry the club spines and the 

 true spines are very distinct, such as those of which photographs are 

 given on plate 42 as figures 1, 2, 4, 5, and 7, and in this case the radial 

 shields remain very large. In others the plates are concealed under 

 an integument which is pierced by the spines and the club spines, 

 and the radial shields may be in part covered by this integument, 

 which more or less restricts their visible surface; this occurs, for 

 example, in the specimen from station 5545 which I figure (fig. 8). 

 The specimens from station 5545 are interesting to compare with each 

 other because of the variations which they show in the appearance 

 of the dorsal surface of the disk; all carry true spines, but in some 

 these spines are rather slender, elongated, and similar to those which 

 are represented on plate 42 as figure 4 ; the plates of the dorsal sur- 

 face of the disk, which do not appear to be covered with integument, 



