Cirsotrema amamiense
Nakayama, 2000
Description:
Dimensions range from 4.1 mm - 13.2 mm high and 6.3 mm - 9.1 mm wide.
Width to height ratio: 01.54:1 ~ 0.69:1
Shell: pyramidal; thick, rather thick; minute to small. Exterior colour dull white. About 9 whorls, convex; protoconch with ~2 whorls exact number unknown; teleoconch with ~7 whorls strongly angled at the shoulder. Spire convex. Suture deep, crossed by thick lamellae. Imperforate: umbilicus closed. Costae are blade-like, surface with numerous blade-like axial costae grouped to form foliated coronation. Occasional irregular and strong varix appearing randomly on the shell. Costae touch the costa below. Base with a distinct ridge formed by the costae. Columella margin reflexed and thickened. Aperture circular; outer lip margin strongly angled at coronation. Operculum black, circular, paucispiral.
Distribution:
Ryukyu Islands, Kii Peninsula Japan ; Aliguay Island, Philippines
Habitat:
at about 100-200 m deep
Type Material:
Holotype (NSMT Mo-71409), height 9.1 mm; breadth 6.3 mm (Figs. 3-6).
Paratype (Noda collection), height 6.2 mm; breadth 4.1 mm. for Cirsotrema amamiense Nakayama, 2000 - Locality: Off Amami-Oshima Island, at about 200 m deep (collected by the R/V Tansei-maru at KT-92-2, STYT-1).. [Nakayama, T., 2000]
Nakayama, T. (2003). pp: 109. Plate 3. Fig. 29-31.
figs 29-31: Cirsotrema (Cirsotrema) amamiense Nakayama, 2000
height 9.1 mm; breadth 6.3 mm (holotype); fig. 31, base
Distribution
as listed in source literature
Sowerby, G. B. II. (1873-1874).
pp: 280. Fig. 3.
Figs. 3-6. Cirsotrema (Cirsotrema) amamiense n. sp.
pp: 280. Fig. 4-6.
Figs. 3-6. Cirsotrema (Cirsotrema) amamiense n. sp.
Nakayama, T. (2003).