“WYVILLEA, n. gen.
Animal a typical Volute.
Shell ovate, cymbiform, thin, rough; spire high scalar; apex mamiliate and irregular; suture canaliculate; mouth large, ovate; inner lip with a widespread thinnish callus; pillar perpendicular, with a very slight turn; it has no teeth, but an abrupt break of the edge about the middle of its length.
This genus differs from Cymbiola of Swainson (the description of which by Adams I have nearly followed) notably in the texture of the shell, which is extremely delicate but rough on the surface, in the suture, which is canaliculate, and in the straight pillar, which is without teeth, but has an abrupt break on the edge. In all the Volutes the last tooth consists of a lamina attached to, or consisting of, the edge of the pillar, the twist on which throws this lamina out as an oblique fold whose abrupt slope looks up the pillar. In Wyvillea, on the other hand, the lamina has scarcely a turn at all, and only presents a tooth in consequence of being suddenly arrested and diminished in size; from this results a tooth whose abrupt slope looks down the pillar.
In connexion with this genus it may be well to recall the Halia of Risso, which has some vague features of superficial resemblance; but in that genus the columellar tooth, which is almost terminal, results from the extreme and sudden twisting of the pillar.
I have not given a detailed description of the animal, as Prof. Huxley has undertaken the dissection and full representation of it in all its parts.”
(Watson, 1882: 332)
