Librariscala millecostata
(Pease, 1861)
Description:
Dimensions range from 2.5 mm - 9.7 mm high and 1 mm - 7.1 mm wide.
Width to height ratio: 0.4:1 ~ 0.73:1
Shell: broadly conical, pyramidal; thin and fragile; microscopic to small. Exterior colour dull white. About 12 whorls, convex, rapidly enlarging, joined; protoconch with ~3 whorls glassy; teleoconch with 5-9 whorls. Spire outline usually concave with angle of 45 - 55 degrees. Suture deeply impressed. Umbilicate: small, narrow. Approximately 40 - 100 costae on the body whorl. Costae are prosocline, threadlike, reflexed to form small tubes, continuing into the small umbilicus, prosocline, thin and wrinkly where not coalesced, threadlike, appearing as a raised line dense, strongly prosocline on later whorls. Costae crests completely reflexed to form tubes. Intercostal spaces spiral threads between axial ribs on early whorls, occasionally also on later whorls of large shells. Axial ribs not prominent at shoulder. Base without spiral cord. Aperture rounded, lip thin, reflexed, however, Jousseaume [1912:226-227] describes it as rather thickened, solid; peristome blunt and circular .
Robertson [1981] observes that 'The shells of Epitonium millecostatum have far more axial ribs than any other epitoniid; the rolled over axial ribs are also characteristic', Brown & Neville [2015:61] state that Limiscala dautzenbergi Jousseaume, 1912 is an 'apparent junior subjective synonym of Epitonium millecostatum (Pease, 1861)'. However, WoRMS [2025] lists Limiscala dautzenbergi Jousseaume, 1912 as an unaccepted name for Epitonium multicostatum (G. B. Sowerby II, 1844). While the description and locality of L. dautzenbergi do not align with those of E. multicostatum, they do concur with the description and distribution of E. millecostatum (Pease, 1861).
Distribution:
Hawaii, Okinawa, Japan; Great Barrier Reef, Queensland; Red Sea, Pakistan; Sri Lanka, Seychelles, Maldives [DuShane, 1990:5]; Gulf of Aden [Jousseaume, 1912]; Red Sea to eastern Transkei [Kilburn, 1985:303]
Habitat:
6-216m [DuShane 1990: 5], Den Hartog [1987:96] citing Robertson [1981: 14] states the species 'seems to feed exclusively on ectodermal mucus of its host, Palythoa spec., a colonial zoanthid'
Etymology:
from mille [latin] = thousand and costatus [latin] = ribbed, in reference to the many fine ribs that cover the shell
Type Material:
Syntype: MNHN 4235, 4236 [as Limiscala dautzenbergi Jousseaume, 1912] - Type Locality: Aden, Périm.. [Brown, L. & Neville, B.D., 2015]
Holotype: NHMUK 1961170 [as Scalaria millecostata Pease, 1861: ~ Limiscala dauztenbergi Jousseaume, 1912.] - Type Locality: Sandwich Islands [Hawaii].. [Brown, L. & Neville, B.D., 2015]
Syntype: Paris Mus. 2710 [as Epitonium dautzenbergi (Jousseaume, 1912)]. [Kaicher, S.D., 1981]

DuShane, H. (1988d). pp: 9.
Librariscala millecostata, holotype Br. Mus. (NH)
1961170, L 9 mm, W 6.5 mm.
Distribution
as listed in source literature





