NAUTIUD^. 
99 
aperture is also seen. The umbilicus is of medium size, someTvhat 
larger proportionally than that of Soweiby's type specimen. The 
periphery is very fiat until near the aperture, where it becomes 
rounded. 
It may be mentioned that Sowerby figured only a portion of his 
type specimen in the ‘ Uiucral Conchologv.’ 
trunccitus would appear to be a somewhat rare species. 
Horizon. Lias (England) ; Upper Lias (France). 
Localities. British. Keynsham, near Bristol, Somersetshire (Sow- 
erby’s type) ; Northamptonshire ; llodborough, Gloucestershire. — 
Foreign. Milhau (Aveyron) ; Eanville (Calvados), Marquise, near 
Boulogne. France. 
Fairly well represented in the Collection, which includes Sowerby’s 
type (“ Sowerby Collection ” — No. 44117 «), figured in the ‘ Mineral 
Conchology.' 
Nautilus astacoides, Young and Bird. 
1828. Nautilus astacoicles, Young and Bird, A Geological Survey of the 
A'orkshire Coast, p. 270, pi. xiii. f. 2. 
1835. Nautilus astacoides, Phillips, Geol. of Yorkshire, p. 160, pi. xii. 
f. 16. 
1837. Nautilus astacoides, Ilunton, Trans. Geol. Soc. vol. v. p. 219. 
1849. Nautilus astacoides, d’Oibigny, Prodrome de Paleontologie Stra- 
tigraphique, vol. i. p. 245. 
1854. Nautilus astacoides, Morris, Catalogue of British Fossils, 2nd ed. 
p. 306. 
? 1874. Nautilus astacoides, Duniortier, Etudes Paleontologiques sur les 
Depots Jurassiques du Bassiu du Bhone, pt. iv. p. 41, pi. v. ffi 1-4 
{not pi. viii. f. 4). 
1876. Nautilus astacoides, Blake, in Tate and Blake’s ^ The A’orkshire 
Lias,’ p. 313. 
Sji. Char. Shell inflated, somewhat compressed at the sides and 
on the periphery, the whorls wider than high, the widest part a 
little below the middle. The umbilicus is rather large, with rounded 
margins. The septa, which number about twenty to a whorl, are 
only slightly sinuous. The s;phuncle is situated a little below the 
centre. The shell is ornamented throughout with strong irregular 
longitudinal lines, crossed by transverse indistinct flexuous lines 
which form a sinus upon the periphery. 
IlemarTcs. The species bearing the closest resemblance to N. asta- 
coides is the N. intermedins of Sowerby ; but in the latter the siphuncle 
is above the centre, and the periphery is very distinctly flattened, 
while the umbilicus is much larger. 
