Description
Author: Jan Delsing
Text ID: 98851
Text Type: 1
Page: 0
Created: 2020-01-31 21:57:51 - User Delsing Jan
Language: EN
Text function: [[t:1388448,textblock=98851,elang=EN;Description]]
Shell size between 5 and almost 17 mm in length, circular or oval, usually callused. Ribs fully developed, of variable number. Dorsal sulcus reduced to a depression. Ribs can be bisected at the sulcus. Spire retracted with a variable number of terminal ribs. Ventral margin slightly and outer labral margin distinctly, roundly callused. Aperture fairly wide. Labrum thickened to a variable degree. Labral teeth coarse and distant or fine and close-set. Fossula developed. Shell colour uniform with the dorsal ribs whitish.
Radulae formula: CI) —1 — 1 — 1 — 1 — 1— (1). Rachidian tooth trapezoidal. The margin of the outer edge is covered with coarse cusps. Lateral teeth slightly wing-shaped with a prolonged, strong, bent cusp on the anterior tip. Inner marginal teeth bent with a long cusp on the anterior tip. Outer marginal teeth atrophic.
The new genus differs essentially from all other triviid genera by the radula morphology. No other triviid genera possess atrophic outer marginal teeth. The dorsal depression distinguishes the new genus from Trivia Broderip, 1837 (type species: Cypraea europaea Montagu, 1808 [= Cypraea monacha Da Costa, 1778]), Pusula, and Quasipusula gen. nov. herein. The taxa of the genera Trivia and Quasipusula lack even a dorsal depression whereas a smooth, wide, bisecting dorsal sulcus is characteristic for Pusula.
Fehse D & Grego J - 2014 - Revision of the genus Pusula (Mollusca Gastropoda Triviidae)