Chlamys iwamurensis Itoigawa, 1955
ITOIGAWA, J. 1955. Molluscan Fauna of the Mizunami Group in the Iwamura Basin. Memoirs of the College of Sience, University of Kyoto [Series B - Geology and Mineralogy], 22 (2): 127-143, pIs. 5, 6. [p. 137, pl. 5, figs. 5, 6]
1955 Chlamys (Chlamys) iwamurensis Itoigawa, 1955
J. Itoigawa, 1955, plate 5.
|
«Shell medium in thickness, suborbicular, slightly convex, about 50 mm. in height, higher than long, subequivalve, equilateral except for ears; apical angle about 95º; sides gently concave, posterior being longer than the length of the anterior sides; ventral margin regularly rounded; left valve sculptured by numerous unequal narrow scaly ribs, also furnished with occasional riblets in some interspaces; incremental line fine, not imbricated; ears very unequal; anterior ear being longer than posterior, trigonal, sculptured by concentric imbricating lines and 11 radiating riblets; posterior small, trigonal sculptured as well as anterior; right valve similar to left except for ears, with byssal notch.
Dimensions: Height, about 52 mm.; length, 49 mm.; thickness, unknown. Holotype: JC 1300046 (from 111, Kamigiri), Paratype: JC 1300039 (from 21, Kamigiri), JC 1300047 (from 111, Kamigiri) Occurrence: Kamigiri (111, 112, 113, 21, 93), Nakanishi (446)... Kubohara sandstone, Hikage (246-1)... Maki siltstone This shell is closely allied to Ch. irregularis (SOWERBY) (1847) but former has the more orbicular shell with the finer scaly ribs. Ch. harimensis MAKIYAMA 1923) is another allied species but it is distinguished from the present new species in having the inflated shell with the stout, coarse and a little imbricated ribs.» JUNJI ITOIGAWA, 1955
|