The Echinoid Directory

Contributed by Simon Coppard, September 2006

Coelopleurus (Keraiophorus) undulatus Mortensen, 1934, p. 166

Diagnostic Features	The test has narrow naked median regions on the interambulacra, consisting of only a naked undulating line on each interambulacrum. These regions are surrounded by club-shaped secondary spines and pointed miliary spines. The undulating lines start from the genital plates, are lavender in contrast to the reddish brown test in this region and stop above the ambitus. Primary spines are highly curved and unbanded; red distally (on the dorsal surface) blending into green proximally, typically just above the spine's collar. The collar's dorsal surface is highly granular with no ridges either side of the central dorsal ridge; the ventral surface has many longitudinal ridges. All secondary spines are club-shaped. Ophicephalous pedicellariae are abundant both orally and aborally, the valves having distal regions that are slightly longer than the proximal regions. These have moderately constricted valves aborally, but are unconstricted orally.
Distribution	Recent, Japan (Sagami Bay and Kyushu).
Species Included	C. (K.) undulatus var. ruber Mortensen, 1934; Recent, Macclesfield Bank C. (K.) undulatus var polymorphus Mortensen, 1934; Recent, Japan
Classification and/or Status	Arbacioida, Arbaciidae, Coelopleurus
Remarks	This species is distinguished from other Recent Coelopleurus by its unbanded spines in conjunction with short, narrow, undulating naked median regions on the interambulacra. It is similar to Coelopleurus maculatus in having club-shaped secondary spines and short, narrow naked median regions on the interambulacra. Mortensen, T. 1934. New Echinoidea (Stirodonta); preliminary notice. Vidensk Meddel. Dansk Naturhist. Foren, Kobenhavn 98, 161-167