首页 › A Manual of Conchology According to the System Laid Down by Lamarck, with the Late Improvements by De Blainville. Exemplified and Arranged for the Use of Students. › 第 30 题 4. Acasta. Three species. Found in sponge, from which, when detached, it cannot stand erect on
account of the convexity of the base.
Shell oval, sub-conic, shaped like a Patella, with six lateral unequal
valves slightly connected; operculum with four valves.
Acasta Montagui.
A. glans.
A. sulcata.
_A. Montagui._ Montague’s Acasta.
Valves erect, triangular, acute, with muricated ascending spines.
A Manual of Conchology According to the System Laid Down by Lamarck, with the Late Improvements by De Blainville. Exemplified and Arranged for the Use of Students. · 第 30 / 258 题