Original taxon: Hyalaea trispinosa.
Most of the synonyms describe the genus: bisulcata, compressa, depressa, mucronata…
« Pretty species, very depressed, hardly more domed below than above; the upper lamina protruding just a little more than the lower one; anterior aperture very narrow, the lateral ones being almost null and terminated on the anterior side of the lateral appendages, which form on each side a very acute point. The posterior extremity extends into a kind of tube, quite long, swollen at its end. » – H. M. F. de Blainville: “Hyale, Hyalaea (Malacoz.)” in F. Cuvier: Dictionnaire des sciences naturelles vol. 22, Paris 1821, p.82.
650m deep, Sardinia Channel. 7mm.
The « below » of Blainville is at right, with its truncated lamina, while the « above » is at left, with its rounded lateral keels on both sides of a central bulge, and the curved upper lamina.
Original pictures provided by A. Nappo (IT).
– (CC BY-NC-SA) –
A specimen pictured near Antibes, Alpes-Maritimes, SE. France. Original image provided by S. Le Bris for iNaturalist – (CC BY-NC).
Original image provided by invertebratist for iNaturalist.
– (CC BY) –
The shells in this genus are much flatter than in Cavolinia.