Zoological Illustrations Series II/Plate 128
MITREOLA.
1. monodonta. 2. terebellum. 3. Mitra acuminata.
MITREOLA monodonta,
The Volute Mitres.
Family Volutidæ. Sub-family Mitranæ. Genus Mitreola. Sw.
Generic Character.
Shell fusiform, smooth; the middle plaits of the pillar largest apex of the spire generally papillary.
Specific Character.
Shell ovate, acute, smooth; spire slightly striated, the tip papillary; outer lip within, gibbous.
Mitra monodonta. Lam. Syst. 7, p. 324.
We feel much obliged to Mr. G. B. Sowerby for calling our attention to the remarkable construction of this Volute Mitre, of which we had not then seen a specimen. We view it as supplying that link of connection between the Volutinæ and the Mitranæ, the Volute and the Mitre shells, which we had long been in search of. Of the genus, however, we know as yet but of two species, represented on the plate somewhat larger than their natural size. We have also added a figure of our Mitra acuminata, to shew how beautifully Mitreola is represented by the fourth type of the genus Mitra, as now restricted, to which type (represented by M. Zebra), acuminata also belongs: both, as prototypes of the Strombidæ, have the outer lip gibbous near the top; but the plaits of the pillar are totally different, while the spire of one is acute, and of the other papillary. M. monodonta is a Grignon fossil: some specimens are so well preserved, that the colours may be traced in the appearance of zebra-like stripes: thus strongly corroborating our views on its true analogies.
MITRA terebellum.
Shell fusiform, turrited, smooth, base striated; channel sub-entire. Mitra terebellum. Lam. Sys. 7, 325. Ency. Meth. pl. 392, a, b, c, d?
Of this Grignon fossil, we have but one specimen: it agrees with Lamarck's description, but not with the figure he quotes; and it may possibly be a distinct species between his M. plicatella and terebellum. The plaits are like those of M. monodonta; but the tip of the spire is acute, and slightly plaited.