52 EOCENE MOLLUSCA. 
siphuncle, by which only the position can be determined, is perfectly marginal. The 
Nautilus Aturi, which I consider to be identical with Nautilus zic-zac, is the type of 
Bronn’s genus, and I therefore retain the name proposed by that author, although I do 
not assent to the accuracy of his generic description. 
The genus Clymenia, proposed by Count Munster for certain Nautiliform remains 
occurring in the transition limestones of Fichtelgebirge, presents nearly the same 
characters as those assigned by me to Afuria; except that in Clymenia the whorls are 
exposed, and the siphuncle is described as narrow; whereas in Afuria the last whorl 
conceals the others, and the siphuncle, at least in 4. z/c-zac, the typical species, is of 
oreat size. 
The genus appears to have been confined to the tertiary epoch, and it is widely 
diffused. It occurs in the Eocene formations of England, France, Belgium, and 
Germany ; in the Miocene deposits in the basins of the Gironde, in Italy, and in Malta. 
It is also found in the Eocene formation in Clarke county, Alabama, (U.S.), and Conrad* 
mentions a cast from the contemporaneous formation near Long Branch, New Jersey, 
resembling Nautilus (Aturia) zic-zac, but more compressed, and which he has referred 
to De Montfort’s genus Pelagus, and has named P. Vanuxemi. De Montfort’s Pelagus, 
however, is described as having “cloisons lobées, persillées, dentelées, &c.” The 
position of the siphuncle is not mentioned in De Montfort’s text; but in the figure he 
has given it is placed on the ventral margin. The shell, therefore, on which the 
genus Pelagus is founded is an Ammonite, and the species constituting the present 
group cannot be associated with it. 
No. 13. Aruria zic-zac. Broun. Tab. IX, fig. la—s. 
Var.a. Navriius z1c-zac. Sow. 1812. Min. Con. vol. i, p. 9, pl. 1, fig. 3. 
Ammonites Waprprert. Van Mons. 1833. L’Institut. 1833, p. 272. 
— — — 1834. Bull. de lAcad. de Brux. tome i, No. 17, 
pp. 113, 118. 
Navritus Desuayest1. De Koninck. 1834. Notice sur un Moule pyriteux du Naut. de 
Desh.; Bull. Soc. Géol. de France; t. iv, p. 437. 
— — Nyst. 1835. Rech. sur les Coq. foss. de la Prov. d’Anvers, 
p- 35, No. 52. 
= — De Koninck. 1837. Desc. des Coq. foss. de l’Argile de 
Basele, p. 1. 
— Aturt. Bronn. 1837. Leth. Geog. vol. ii, p. 1123, pl. 42, fig. 17a—e. 
-- z10-ZAC. Desh. 1837. Desc. des Coq. foss. des Env. de Paris, vol. ii, p. 765, 
pl. 100, figs. 2, 3. 
CryMenta ztc-zac. Michelotti. 1840. Amnal. Scient. reg. Lomb. Venet. p. 6. 
* Conrad’s “ Observations on the Eocene formation, and description of one hundred and five new fossils 
of that period, from the vicinity of Vicksburg, Mississippi,” published in the Journal of the Academy of 
Natural Science of Philadelphia. 
