The size of the shell varies between 50 mm and 100 mm. The shell has a trochiform shape. It is as high as broad. It has a flat base. It shows moderately numerous spiral lines. It is pale yellow, beautifully flamed with 11 red whorls that are regularly increasing. The penultimate whorl has 8 lirae above, 2 in and 2 under the slit fasciole. These lirae are beset with weak nodules, about 3 times as long (in the direction of the spiral) as high or broad. The body whorl has a blunt angle at its base. This base contains 20 concentric lirae, and in the middle a deep pit or "false umbilicus". On the outside it is white, on the inside it is pearly. The thick, pearly columellar margin is S-shaped.[3]
Distribution
M. beyrichii is endemic to the coastal waters of Japan.[4] and China
Mikadotrochus beyrichii (Hilgendorf, 1877). Museum specimen, Naturalis Leiden.
References
^Hilgendorf in Sitzungsb. d. Gesellsch. Naturf. Freunde Berlin, 1877, p. 72.
^Oliver, A.P.H. (2004). Guide to Seashells of the World. Buffalo: Firefly Books. 17.
Dautzenberg, Ph.; Fischer, H. (1898). Note sur le Pleurotomaria beyrichi. J. conchyliol. XLVI: 218–224, plate XI
Williams S.T., Karube S. & Ozawa T. (2008) Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined. Zoologica Scripta 37: 483–506
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