292 
Class — C ephalopoda. 
Order— TETRABllANCHIATA. 
Family- NAUTILID^. 
Oenus — NAUTILUS, Hreynius^ 1732. 
(Dissert. Phys. Polythalamiis.) 
Obs. Nautilus, or one of its sections, is represented by a decorticated fragment, 
too imperfect to figure, of a small sbell nearly an incb in diameter. There are eight 
septa visible, and, for the size of the specimen, a large umbilicus. This is the 
only indication of this genus I have met with in the Queensland Permo-Carboniferous 
rocks, with the exception of the following peculiar species. 
Log. and Horizon, llockhampton District* {G. W. Be Vis; Colin. De Vis) — 
Qympie Beds. 
NAUTiLtrs ? AMMONiTiFOEMTS, sp. nov., PI. 39, fig. 9; PI. 41, fig. 9. 
Sp. Char. Shell planorbiform, apparently much depressed, of many closely coiled, 
convex, uniform, narrow, tube-like whorls in one plane, and, with the exception of the 
body-whorl, expanding but very slowly. The latter is much flatter and broader than 
the others, and has lost the tube-like appearance of the inner and older whorls ; aperture 
unknown. Surface of all but the body-whorl with angular, direct, transverse ridges, 
or costae, separated by interspaces of more than their own width, but on the latter they 
become flattened, depressed ribs, somewhat sigmoidal, presenting a very different 
appearance. 
Ohs. A very peculiar shell, which from its general appearance would seem to 
be more nearly allied to the Cephalopoda than the Q-asteropoda. Not the least peculiar 
feature is the remarkable regularity of the coil in one plane, whereby the enlargement 
of the whorls is hardly perceptible until the body-whorl opens out. There are no septa 
visible, but, on the other hand, the appearance of this shell is quite different to that of 
any of the Euomphalida), and the sudden expansion of, and change of ornament on the 
body chamber, cause me to regard it as a Cephalopod. There are traces of a ventral 
keel, but no spiral striae. The costae on the older chambers are at right angles to the 
coil, but the ribs on the last chamber assume an oblique direction. The last whorl, and 
the inner whorls (PI. 39, fig. 9), are frequently found disconnected, when they might be 
readily mistaken for two distinct species. 
I have been much perplexed with regard to a genus for this fossil, and it is only 
placed in Nautilus as a matter of convenience, as it is obvious that no I’eal relation 
exists between the two. As a matter of fact, in outward appearance, these fossils 
present an exact resemblance to Bituites, especially that section named by Barrande 
Oph.idioceras.\ There is the same coil-like form in one plane, tube-like whorls, and 
separate transverse costae. But Lituites is a Silurian genus and confined to 
rocks of that age throughout the world. Otherwise, had intermediate Devonian 
species existed, I should have been tempted to refer the present species to 
it. On the other hand, this may be one of those extraordinary survivals of 
an old genus for which the Australian Palseontological record is becoming noted. 
* Bee note, p. 199. 
t Syst. Sil. Centre Boh^me, 1865, ii., C^ph. le. Ser., Pis. 1 107, t. 45, f. 13, 17, 22, 23, 24, &c 
