History of British animals - University of Guam Marine Laboratory

338 MOLLUSCA. TORNATELLADiE. Bellebophon." Shell glossy, white, veined like ivory in a longitudinal direction, andfurnished with eight or nine reversed volutions, slightly tapering to an obtusepoint ; the lower whorl occupies two-thirds of the shell ; the apertureis narrow, not quite half the length of the shell ;and the columella possessesone plication. Length a quarter of an inch ; breadth one-third of its length."Mont.— This species, in all probability, is likewise the type of a new genus.Gen. BELLEUOPHON. — Shell spiral, involute, the lastwhorl enclosingthe others ;aperture arched, extremitiessimple, with a sinus in the middle of the outer lip.*With a mesial band.1. B. hiidcus,— Globose, expanded ;closely striated, the striae sharp, elevated,passing obliquely from the mesial band, which is flat, broad, with itssides denned by sharp depressed lines ; a central cavity on each side ConchyliolithusNautilites hiulcus, Mart. Pet. Derb. t. xl. f. 2.— Bel. hiulcus, Sower.Min. Conch, t. cccclxx. f. 1.— Carboniferous limestone, Derbyshire.2. B. tenuifascia — Spherical, with a well defined central cavity, finely striated; mesial band linear, elevated.— Conch. Naut. hiulcus, var. c. Mart. Pet.Derb. p.15.— B. ten. Soiver. Min. Conch, t. cccclxx. f.2, 3— Carboniferouslimestone, Derbyshire and Yorkshire.3. B. costalus.— Globose, expanded, subcarinated, with slender sharp ribsdiverging from the undefined broad convex band ; with a central cavityConch. N. hiulcus, Mart. p. 15, t. xl. f. 1. Park. Or. Rem. iii. 141. t. x. f. 6,7—B. cost. Sower. Min. Conch, t. cccclxx. f. 4 Carboniferous limestone, Derbyshire.4. B. decussatus—Shell somewhat ovate longitudinally, with numerousspiral ridges, crossed by finer ones, giving the points of union a subtubercularaspect mesial band rounded, ; longitudinally striated, decussated by thetransverse fine ridges, which in crossing have a concave bend—In my cabinetfrom slate-clay of the coal formation, Linlithgowshire.5. B. striatus— Longitudinally ovate ;with numerous, fine, slightly rough,apiral ridges : mesial band slightly flattened, and longitudinally striated.This species differs from the last in the mesial band being more elevated,and in the nearly total absence of the transverse ridges. In one specimenthere is a thick inner lip spreading on the surface of the last whorl.—Fromthe same place as the last.** Destitute of a mesial band.6. B- apertns — Nearly spherical; sides of the aperture expanded; shellsmooth, thick ;with a well defined central cavity—Sower. Min. Conch,t. cccclxix. f. 1.— In Carboniferous Limestone, Lowth. I have a specimen fromcarboniferous limestone in Linlithgowshire, agreeing in form with one presentedto me by Mr Wright from Lowth.7. B. cornu-arietis.— Elongated; sides of the aperture expanded shell ; verythick, smooth, faintly marked by laminated— the lines of growth. The shell, when a littlecorroded, becomes coarse and Nautilus, Ure, Hist. Ruth. 308.t. xiv. f. 8 B. corn. Sower. Min. Conch, t. cccclxix. f. 2—Mr Sowerby'sspecimens are from Limestone, Kendal ;mine are from Carboniferous Limestone,Linlit hgow sh ire.8. B. Urii Globular; sides of the aperture expanded; shell smooth, regularlysulcated spirally ; the furrows shallow, the ridges rounded.—-Nauti-