fuelTL GaIL. (A: [tl—-240 - LE> . XK RK). lPSb. 
PROSOBRANCHIA'TA. 18] 
In a fossil state, the genus first appears in the cretaceous formations, in which five or 
six species are stated to occur; but during the tertiary epoch, the species became much 
more numerous. More than forty have been described from the eocene strata, and a 
still greater number from the more recent deposits. From the English eocene strata, 
four species have been noticed ; of these, three, described by Mr. Sowerby in ‘ Mineral 
Conchology,’ appear to be confined to this country ; the fourth occurs at Bracklesham, 
and is identical with a species abundant in the Paris basin. Three additional species 
are now described for the first time. 
No. 118. Mirra scasra. Sowerby. Tab. XXIV, fig. 6 a—c. 
SMALL LATTICED LYMINGTON WHELK, Pet. 1764. Gazophyll., t. 73, fig. 9. 
Buccinum scaBricuLum, Soland. (non Gmel.) 1766. Brand. Foss. Hant., p. 15, fig. 20. 
Mirra scaBra, Sow. 1823. Min. Con., vol. iv, p. 142, t. 401. 
= = Morris. 1843. Cat. Brit. Foss., p. 151. 
— _ D'Orb. 1850. Prod. de Paléont., vol. ii, p. 355, No. 313. 
— — Morris. 1854. Cat. Brit. Foss. (2d edit.), p. 258. 
M. testa ovato-acutd, costulis longitudinalibus et lineis transversis sese decussantibus 
scabratd, ad basin profunde emarginaté: spird conicd, apice obtusiusculo: anfractibus 
convexis, marginibus posticis tenuibus: aperturd elongato-ovali, postice angustatd ; labro 
incrassato, sub-marginato, intus crenulato ; columella quadri-plicata, plicis distantibus, fere 
transversis ; labit ared pliciferd incrassatda. 
Shell ovately oblong, slightly ventricose, deeply notched at the base, with a conical 
spire, terminating in a small, slightly obtuse apex, formed of two smooth, nearly round, 
embryonal volutions; whorls seven or eight, exclusive of the embryo, and covered 
with irregular longitudinal ridges, and conspicuous lines of growth, decussated by 
sharp, transverse, raised lines slightly thickened at the points of decussation, roughen- 
ing the surface of the shell; the posterior margins are thin, and pressed against the 
preceding whorls. The aperture is of a lengthened oval shape, narrowed posteriorly ; 
the outer lip sharp and thin in the young shell, but irregularly thickened at maturity, 
and presenting an obscure, slender, raised border along the outer edge, and a blunt 
triangular tooth-like callus on the inner edge, near the posterior extremity; the colu- 
mella is furnished with four distant, nearly transverse folds, of which the anterior one 
is much the smallest; and some specimens also present one or two obscure transverse 
lines towards the posterior part of the columella. The inner lip is very narrow, and 
much thickened where the folds are placed. Owing to the great depth of the notch, 
the base of the shell is more bent backwards than is usually the case in the fossil 
Mitre, and presents the prominent. crest or ridge which, as we have seen in the 
Volutes, always accompanies a deep notch. 
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