EASTERN TROPICAL PACIFIC ASTEROIDEA. 109 



at base and with a maximum width, about 12 mm. from base, of only 4 mm.; 

 genital area very short only about one tenth of ray-length, covered closely by 

 plates, spinelets, and pedicellariae like those of disk but notably smaller; be- 

 yond genital area, minute pedicellariae continue for a few joints only on the 

 dorsal surface ; along sides of ray however, they continue more or less abundantly, 

 and distally they again invade the dorsal surface, so that the tips of the rays 

 are apparently enclosed in skin densely covered with these very minute pedi- 

 cellariae. 



Adambulacral plates long and narrow, about 2 nam. by .75, so Uttle concave 

 on the fiu-row-side that they are almost cyhndrical; there is a moderately de- 

 veloped peak at the inner, distal corner; their armature consists of two spinelets, 

 one of these is placed on the inner peak of the plate and extends diagonally across 

 the furrow, while the other is near the center of the plate, or a little distal to it, 

 on the actinal surface; the fiirrow-spine is short and thick, not much longer 

 than width of furrow, and bears a number (5-8) of small pedicellariae; the 

 actinal spine is very slender, only about 3 mm. long at base of arm but becoming 

 5 mm. long on distal part of ray ; it is very acicular but is clothed in loose skin, 

 densely covered with very minute pedicellariae and unless this skin is damaged, 

 the slenderness of the spine is not apparent. Above every other actinal spine 

 is an inferomarginal spine which at base of arm is only 4 nun. long but reaches 

 a maximmn length of at least 7 mm. distally; the actinal spines overlaid by the 

 inferomarginals are always noticeably smaller than those which are unaccom- 

 panied, but the latter are not so large as the inferomarginals; Uke the actinal 

 spines, the inferomarginals are clothed in thick, pedicellaria-covered skin. 

 Tube-feet moderate, in pairs opposite distal part of adambulacrals ; pores 

 about 1 mm. across. Oral plates short, moderately high at distal end with a 

 keel along midradial line; each plate carries near distal end a long, slender skin 

 covered spine, about 5 mm. long, distinctly thickened at tip; at distal outer 

 corner a smaU, pedicellariae-bearing spinelet like that of the adambulacral plates ; 

 and at inner end, two, or rarely tlu-ee, short, more or less curved, flattened, 

 wide spinelets, much wider at tip than at base; some are so wide at tip as to 

 be almost fan-shaped; inner is much smaller than outer; the latter may be over 

 a millimeter long and nearly a millimeter wide at tip; these inner oral spines 

 are not skin-covered and carry no pedicellariae. Color, in alcohol, nearly white. 



Station 4740. Eastern Tropical Pacific, 9° 2' S., 123° 20' W., 2,422 fms. Bott. temp. 34.2°. Dli. gy. 

 glob, and rad. oz. 



One specimen. 



