696 
to the Expedition, informed me was in situ. The shells are too much worn hy weather- 
ing to attempt a specific determination, but they seem to have more of a Tertiary than 
a Secondary aspect. 
At Observatory Bend, Strickland Eiver, numerous travelled nodules and small 
boulders were collected, revealing a totally different kind of life, chiefly the remains of 
Ammonites. But amongst them is a bivalve, either an A.uceTla or an Inoceramus. If 
the latter, it is decidedly of the type of the Cretaceous I. concentricus. Unfortunately, 
the characters of the hinge cannot be ascertained. These fossils are, however, of little 
importance when compared with the Ammonites. Out of a number of nodules, in 
which the fossils are indicated by impressions or casts, a fairly representative series has 
been selected, containing four more or less recognisable species, or at any rate species 
which can be referred to one or other of the sections into which the old genus 
Ajmmonites is now broken up, and the facies of which is sufficiently clear for broad 
generalisation. 
The section StepJianoceras is largely represented by an Ammonite of the group 
of A., calloviensis, Sby., and even closely allied to that species. At first sight 
the primary costsc springing from the umbilical margin are not very apparent in 
our specimens, but attentive examination reveals them as in D’Orbigny’s figure * * * § of 
this species, but closer together, and therefore more numerous. It would appear that 
the umbilicus is smaller than in the European form, and less telescopic, wherein these 
shells approach Steplianoceras transiens, 'W’aagen,t from Kutch, or 8. may a, J. de 
C. Sby.J They possess the same form and arrangement of ribs as in the latter, which 
commence quite simple at the umbilicus, and break up at about equal distances into 
bundles of three, whilst the shell is rather more compressed. 
The next species partakes of the form of StepJianoceras Blagdeni, J. Shy., 
or equally well with 8 . coronatus, Brug. It is a small shell, with the costm of 
the back and the tubercles less marked than in the above species. On the other 
hand, the cross-section of the whorls clearly indicates its relation to this group. 
The specimen also partakes, in some degree, of the features of the shell figured by 
D’Orbigny as Ammonites Sumpliresianus ; § but the umbilicus in the former is deeper. 
A comparison may also be made with Quonstedt’s figure of 8 . corona tus jj. 
Two rather well-marked Ammonites appertain to the group StepJianoceras 
laniellosum, J. de C. Sowerby,iy but, as compared with that species, possess a 
wider and more open umbilicus, with the costae of the back less upwardly curved 
and more horizontal; in fact, the costae are all more direct, and lack the sigmoidal 
curve on the flanks of 8. lamellosus. Erom 8. Qrantianum, Oppel, as figured by 
Waagen, the costae seem to be finer, but to J. de C. Sowerby’s figure of this species 
under the name of A. Herveyi,** our fossils bear a close resemblance, and also to 
D’Orbigny’s figureff of the same, in the breadth and nature of the back. An aflhiity is 
also to be detected in the same Author’s Ammonites macrocepJialus,%X but not with that 
of Waagen under the same name. A third fragment, however, possesses costae as coarse 
as those shown in the latter’s illustration of StepJianoceras Qrantianum. 
* Pal. Pranf. Terr. Jur. Ceph., i., Atlas, t. 162, f. 10. 
t Pal. Indica (Jurassic Fauna of Kutch), i. Ceph., t. 32, f. 2a. 
f Trans. Geol. Soc., v. (2), t. 61, f. 8. 
§ Pal. Fran9. Terr. Jur. Ceph., i.. Atlas, t. 134. 
li Cephalopoden, 1849, Atlas, t. 14, f. 4a. 
T Trans. Geol. Soc., v. (2) t. 23, f. 8. 
** Trans. Geol. Soc., v. (2), t. 23, f. 6. 
tt Pal. Fran;. Terr. Jur. Ceph., i.. Atlas, t. 150. 
X Pal. Franj. Ter. Jur. Ceph., i.. Atlas, 1. 151. 
