MITRANÆ Pl. 5.
1. Tiara isabella. 2. sulcata.
It is highly probable that the Mitres, like some other carnivorous marine animals, seek their prey, and habitually reside, in the deep recesses of the ocean. Instances are recorded of individuals having been brought up from great depths; and notwithstanding the number of species, of which we already know near 150, very few are common.
TIARA isabella.
Fawn coloured Mitre.
Order Zoophaga. Family Volutidæ.
Sub-Family Mitrianæ. (G. Mitra. Auct.)
Generic Character.
Animal——
Shell turrited, fusiform, the base contracted and slightly recurved; pillar with 4-5 plaits, the upper plait sulcated: outer lip smooth, or entire. Aperture narrow, striated within, and presenting an internal groove at its upper extremity. Nobis.
Types of Form.
1, M. Corrugata. 2, Regina. 3, Sanguisuga. 4, Microzonias. 5, Isabella.
Specific Character.
Ti. (Ty. 5) Shell slender, fawn coloured, unspotted, marked by slender crowded, transverse, convex ribs, the interstices deeply cancellated; inner lip wanting, outer lip crenately undulate; pillar 5 plaited.
This genus, in short, is now become too overloaded, even for the purposes of artificial arrangement: but we refrained from characterizing any other group than Conohelix, until we analized the remainder. Tiara appears to be the second, or sub-typical group. The subordinate section, or type of form, represented by T. isabella, includes several little known shells, all marked by delicate transverse ribs and longitudinal striæ: the outer lip is not strictly toothed or crenated, but is merely undulated by the external sculpture: this subordinate group in Tiara, is aberrant: all the species whose habitat we know, have come from the Pacific Ocean.
Tiara isabella is a shell of the greatest rarity. Our drawing was made from a specimen (presumed unique) sold at the Bligh Sale for 3l. 3s. It was stated to come from New Holland, and is now in the Manchester Museum.
TIARA sulcata.
Sulcated Mitre.
Tiara. (Ty. 5.) Shell marked by distinct, carinated, remote transverse ribs, the interstices concave: pillar three plaited, epidermis brown.
For this new and very distinct species, we are indebted to Mr. Bulwar. It was collected on the Pacific side of the American Isthmus. The central line indicates the true size of our specimen.