HAUER ON THE CEPHALOPODS OF THE SALZKAMMERGUTS. 15 
red marble of Hallstatt, is noticed. A fragment, too imperfect 
to permit of the genus being certainly determined, is referred to 
Clymenia, of which it would evidently form a new species. Nau- 
tilus is represented by three species, NV. mesodicus, Quenstedt, N. re- 
ticulatus and N. acutus, with some doubtful fragments, one of which 
much resembles in form the N. elegans, Sow., and like this, has the 
surface covered with fine transverse wrinkles, but the siphon per- 
fectly central. Of Orthoceras three species are certainly found, O. 
alveolare, Quenstedt, O. latiseptatum and O. salinarium, besides 
some doubtful species, the specimens being imperfect, but probably 
O. regulare, O. striatulum, v. Minster, and O. ellipticum, v. Min- 
ster. There are probably two species of Belemnites, which cannot 
be definitely determined. One has an arrow-shaped sheath, exactly 
like the B. hastatus, Blainville, and is above two inches long and 
four lines thick ; the other, about as long, has a very sharp- pointed 
conical sheath, and may be compared with the B. unisulcatus, Blaim- 
ville. Ona polished specimen of marble from the Steinbergkogel, 
some oblique sections of Belemnites are visible, but the species can- 
not be determined. As, notwithstanding the observations of Dr. A. 
Boué, the occurrence of Orthoceratites and Belemnites in the same 
formation with Ammonites has been frequently doubted, and is of 
considerable geological interest, we give the following notices on this 
_ subject. In the royal Montanistic Museum is a slab of marble, on 
one side of which is a specimen of the Ammonites Metternichii 24 
inches in diameter, figured in pl. 2 of the work before us. In con- 
sequence of decomposition the markings of the lobes are well seen. 
The chambers are filled with red marble, whilst the remaining por- 
tions of the shell are converted into white calespar. In this speci- 
men the whole shell is full of dividing septa, so that the last cham- 
ber in which the animal lived must be wanting. Were this added 
in proper proportion, the whole shell would be nearly three feet in 
diameter. 
On the same slab there are an extraordinary number of other fossil 
organisms, exposed by the weathering of the stone. This specimen 
alone is sufficient to remove the doubts so often expressed regarding 
the union of Ammonites and Orthoceratites m the limestone of the 
Austrian Alps. On it three distinctly recognizable Orthoceratites 
appear. The first, near the umbilicus of the large Ammonite; is but 
imperfectly represented in the figure. Its point is broken off, but 
there may still be perceived three of the usual chambers, then one 
considerably smaller, and then the last large chamber in which the 
animal lived. According to M. von Barante, who has recently 
examined the numerous Orthoceratites of the Bohemian transition 
formation in a very careful manner, the frequent occurrence of a 
chamber considerably smaller than the others immediately before the 
last may be thus explained, as he stated personally when inspecting 
the specimen now under consideration. The last partition continues 
to move forward by a constant deposition of calcareous matter on its 
outer surface towards the opening of the shell, and a removal of it 
from the inner surface till the cavity has attained its normal size, 
