trispinosa (de Blainville, 1821)
|Maximum size: 9 mm shell length (Kay, 1979).
This species has transparent shells edged in amber. They are broadly
diamond-shaped and are usually decapitate with the broken apex closed
by a septum. They resemble shells of Diacria major
but the lateral spines are perpendicular to the long axis of the shell
and the portion of the shell apical to the lateral spines is relatively narrow.
Fragments of Diacria trispinosa shells are rare in sand samples.
Taxonomic notes: Intact shells (and most fragmentary material) seem closer to Diacria major than to D. trispinosa
as illustrated in Janssen, et. al. (2019). However, some fragmentary
material from Maui (and elsewhere?) is probably this species. The shell
illustrated in Kay, 1979 also seems closer to D. major though it's
somewhat ambiguous. Janssen, et. al. (2019) consider Diacria maculata to be a synonym.
Observations and comments:
1: ( )