342 
NAUriLOIDKA. 
afforded by this specimen as to the characters of its siphuncle is 
not quite satisfactory ; but the characters of the septa are so clearly 
those of Aturia that one feels justified in placing both this and Par- 
kinson’s type specimen at least provisionally in the present genus. 
The sudden appearance in the Tertiary fauna of such a highly 
specialized form as Aturia is not a little remarkable, because at that 
time there was a comparative scarcity of 2\autili, and such as did 
exist were of the ordinary type, hut in spite of the singularity of 
the characters presented by the septa and siphuncle, there is no 
reason to doubt the close relationship between Aturia and the typical 
jSlaiitili of the Eocene and of the present seas. If it should be 
found, upon examination of more perfect specimens, that AluruL 
ParTcinsoni possessed a cylindrical (non-invaginated) siphuncle in 
all stages of growth, the species might then be regaided as a sub- 
genus of Aturia, allied to the latter by its septal characters, and 
forming a connecting-link (as suggested by Edwards) between Sau- 
tilus and Aturia. 
Aturia ziczac, J. Sowerby, sp. 
1812. Nautilus ziczac, J. Sowerby, 31iii. Conch, vol. i. p. 12, pi. i. 
(lowest figure). 
1833. Ammojiitcs Wapperi, Van Mons, L’lnstitut, p. 272. 
1834. Ammonites Wapperi, Van Mons, Bull, de I’Acad. de Bruxelles, 
vol. i. no. 17, pp. 113, 118. 
1834. Nautilus linyulatus, v. Buch, Neues Jahrbuch fiir Min. &c. p. 634 
(footnote). 
? 1834. Nautilus Alahamensis, Morton, Synopsis of the Organic Eemains 
of the United States, p. 33, pi. xviii. f. 3. 
1836. Nautilus ziczac, 'Wetherell, London and Edinburgh Phil. Mag. 
and Journ. of Science, ser. iii. vol. ix. p. 465. 
1836. Nautilus ziczac, Buckland, Bridgewater Treatise — Geology and 
Mineralogy, vol. i. pp. 359, 360, vol. ii. p. 63, pi. xliii. fi‘. 3, 4. 
1837. Nautilus zigzag, Leshayes, Bescr. des Coquilles Fossiles des En- 
virons de Paris, vol. ii. p. 765, Atlas, pi. c. ff. 2, 3. 
1837. Nautilus DeshayesU, de Koninck, Bescr. des Coquilles Fossiles 
de I’Argile de Basele, Boom, Schelle, &c. (iSouv. Mem. de I’Acad. 
de Bruxelles, vol. xi.), p. 5, pi. iv. 
1839. Nautilus zigzag, v. Buch, Ueber Goniatiten und Clymenien in 
Schlesien (Akad. d. Wissensch.), p. 158, pi. — . fi‘. 6, 7, not f. 8. 
1840. Nautilus lingulatus, Quenstedt, Neues Jahrbuch fiir Min. &c. 
p. 290, f. 7. 
1845. Nautilus zigzag, Nyst, Bescr. des Coquilles et des Polypiers Fos- 
snes des Terrains Tertiaires de la Belgique (Memoires Couronnes 
et Mem. des Savants Etrangers, publies par TAcad. Boy. des 
