History of British animals - University of Guam Marine Laboratory

230 MOLLUSCA. CEPHALOPODA. Nautilus.10. N. obesus— " Gibbose, unibilicate, plain; back broad, flat; mouthlarge, squarish ;septa very numerous, not recurved ; siphuncleenearlytral."— cen-List. Conch. 1048. ? Soivcr. Min. Conch, t. cxxiv. (transversely ;rsely ovalInferior Oolite, Norton-under-Ham.11. N. bilobatus.—" Subglobose, umbilicated; septa two-lobed ; aperturethree or four times as wide as long." Margin a little flattened ; umbilicussmall, nearly cylindrical ; syphon central. — Sower. Min. Conch, t. ccxlix. f. 2,3—In the Limestone of the Old Red Sandstone, Closeburn, Dumfriesshire.12. N. regalis.—" Gibbose, plain, not umbilicate; front flattish ;sides convex; aperture rather wider than long." — Sower. Min. Conch, t. ccclv.— InLondon Clay.13. N. radiatus.— "Gibbose, umbilicated; surface marked with curved radiatingundulations ; sides and front rounded ; aperture orbicular, deeplydented."— in-Sower. Min. Conch, t. ccclvi. — In Green Sand, Maltor.14. N. Wrightii.— "Gibbose, smooth, rounded extei'iorly, partitions distant,slightly waved ; syphon nearer the exterior than the centre of the chamber :shell increasing rather suddenly."— Flem. Wern. Mem. iii. 96. I owe thespecimen of this species which I possess to Samuel Wright, Esq., who foundit in the Transition Limestone, Cork. It bears a near resemblance in form toJV. elegans.In the twelve following species, the inner whorls are more or less conspicuous,in consequence of the body-whorl not clasping the inner whorls socompletely as in the preceding species.15. N. discus " Depressed, edge flat, aperture oblong, volutions not concealedby each other." Outer edge of the aperture narrower than the innerone, and" notched by a marginal groove ; syphon near the inner edge—Sower.Min. Conch, t. xiii.— In Carboniferous Limestone, Kendal.16. N. intermedins.— " Gibbose, umbilicate, concentrically striated; backbroad, flattened, mouth squarish:siphuncle edge."—nearest the externalSower. Min. Conch, t. cxxv.— In limestone in the Lias at Keynsham.17. N. striatus.— " Slightly depressed; umbilicate; concentrically striated; aperture half the diameter of the shell, nearly orbicular."—The whorlsincrease rapidly ; the front a little compressed the ; strife elevated.— Soivcr.Min. Conch, t. clxxxii—In Lias, Lyme ltegis.18. N. penlagonus "Discoid, subcarinated ; inner turns partly concealed;aperture orbicular, obscurely 5-angled, and impressed by the preceding whorl,nearly half the diameter of the shell." Sides a little flattened ; septa notvery concave, with a central siphuncle."— Sower. Min. Conch, t. ccxlix. f. 1.In limestone of the Old lied Sandstone, Closeburn.19. N."tuberculatum Discoid, thick, largely umbilicate; one row of largetubercles on each side ; front rounded ; aperture transversely elongated, 2-angled." Sower. Min. Conch, t. ccxlix. f. 4—In the limestone of the OldRed Sandstone, Closeburn.20. N. Luidii Whorls apparent, rounded with longitudinalserrated striae ;septa concave, with the syphon placed near the exterior margin— Martin,Petrificata Derbiensia, t. xxxv. £ 12.—In clay in the Coal formation, Derbyshire.21. N. ingens.— Volutions three, nearly external, even, round, graduallytapering; septa oblique, slightly waved—Mart. Pet. Derb. t. xli. f. 5—InCarboniferous Limestone, Derbyshire. This is probably the species which Urerefers to in his Natural History of Rutherglen and Kilbride, p. 307. " The