shell, slender form
Evalea stearnsiella (Pilsbry, 1918)
|Maximum size: 3.4 mm shell
shells of this species are relatively thick and conical. Young, unworn
shells have prominent spiral cords on the apical whorls with the apical
cords progressively more nodular and the abapical cord smooth. Mature
shells usually show only a few
narrow spiral striae on the latter whorls, possibly due to wear. There's
a prominent, shelf-like fold on the columella and five or six ridges
inside the aperture. The angle of coiling is variable.
of Evalea stearnsiella
are moderately common in beach drift.
Live animals are occasionally found in shallow rocky habitats.
According to Kay (1979), shells can be found in sand samples down to 40
m (131 ft).
Maui, Oahu, French Frigate Shoals and Midway.
Taxonomic notes: This species is listed in Kay, 1979 as
Odostomia stearnsiella. It's probably also listed in Severns, 2011 as Odostomia kahoolawensis (the illustrated shell appears to be within the range of
variation of young, E. stearnsiella and, in our opinion, Kay, 1979 was probably correct in synonymizing Odostomia kahoolawensis with O. stearnsiella). Kay, 1979 appears to be incorrect
in suggesting that Odostomia syrtites is a synonym of Miralda scopulorum due to its greater number of basal cords. However, the illustration of that species in Pilsbry, 1918 and Severns, 2011 (as Miralda syrtites) may fall within the range of variation for young E. stearnsiella. It is also likely that the shells listed as Elodiamea sp. and Miralda cf. idalima
(Melvill, 1896) in Severns, 2011 are this species with the latter referring to the slender form (see photo).
The figure of the latter species in Melvill, 1896 shows more and
finer spiral cords. John van Aartsen stated that he thinks the
slender form may be a separate species. (pers. com, 2012). However,
there appears to be a significant amount of intergrading in the angle of
coiling. So, we're leaving them together pending further work.
Photo: CP: Kahului Harbor, Maui; June 15, 2015.
Observations and comments:
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