CrpuHALopopa.] UPPER PALZOZOIC MOLLUSCA. DDT 
periphery to the umbilical edge of the same septum, would touch the middle of the following septal edge; internal 
surface of each septum divided into two deep, rounded, hemispherical pits, one on each side, separated by a narrow, 
very prominent, rounded elevation, extending from the tongue-shaped sinus of the outer margin to the opposite 
point of the inner margin, nearly in the middle of which elevation is the very large siphuncle. Diameter of 
very small specimen about seven lines, proportional width of mouth 4, antero-posterior diameter of mouth “, 
diameter of umbilicus *°. 
Why Mr Sowerby should have re-described this species under the new name JN. clitellarius in the 
Geological Transactions, and why authors generally should have adopted it in preference to the one given so 
long before, with a very good figure in the Mineral Conchology, I am unable to explain. The species is so 
strongly marked by the conformation of its septa, that it is needless to compare it with any other. The external 
form is nearly that of the 1. globatus ; occasionally a thin mesial ridge is perceived on some parts of the casts. 
The umbilicus is too small, I think, in the figure in the Geological Transactions; but those of the Mineral Con- 
chology and Geology of Russia are correct. 
Position and Locality—Rare in the carboniferous limestone of Lowick, Northumberland. 
NAUTILUS CARINIFERUS (Sow.) 
Ref—Min. Con. t. 482. f. 3. 
There is but one fragment of this species in the collection ; it is too imperfect for description. 
Position and Locality.—In the carboniferous limestone of Kendal. 
Nautinus (Discites) COMPLANATUS (So2.) 
Ref—Sow. Min. Con. t. 261. 
The originally figured type specimen of this species, collected by Prof. Henslow, is now in the Cam- 
bridge Collection; and I examined it with great interest, as it was the only Nautilus of the subgenus Discites, 
which was supposed to have had a convex periphery, and it was also (judging from the figure) remarkable 
for having an angular sinus in the edges of the septa at some distance from the edge of the umbilicus, 
where they seem to incline in a direction contrary to that of all known species. I find, however, that there 
is no reasonable ground for supposing these characters to exist. The specimen is preserved in the Posidonia 
limestone beds, and, like the other fossils of those beds, squeezed flat by pressure, and obviously very much 
flatter than natural. The substance of the specimens is only a thin film, of one side, and giving no mate- 
rials for Mr Sowerby’s engraved section of the periphery, which may as well have been concave as convex. 
The edge of the umbilicus is not sharply defined on the chambered portion, as in Mr Sowerby’s figure ; 
and on the contrary, the probability is rather that the angulated edge of the umbilicus exactly coincided 
with the angular sinus of the septa which he represents. The measurements of the figure in question are 
not quite exact; and as the proportions of the sides of the whorls to the umbilicus are not very remote from 
those of JZ. discus, I feel more inclined to suppose that JV. complanatus is a specimen of that species some- 
what distorted by compression, than to admit it as a species with the characters heretofore assigned to it. 
Position and Locality.—Not very uncommon in the black carboniferous limestone of the Isle of Man. 
NAUTILUS coRONATUS (J/°Coy). 
Ref—M Coy, Synop. Carb. Foss. Irel. t. 4. f. 15. 
Des.—Discoid, of about three very rapidly enlarging whorls, half exposed in a very deep, wide, conical 
umbilicus ; edge of the umbilicus carinated by the meeting of the very broad, slightly convex periphery at 
an acute angle with the slightly convex steep sides of the umbilicus, the line of junction being slightly rounded, 
and divided into numerous blunt, oval, compressed tubercles, elongated in the direction of the spiral edge of the 
umbilicus, rather less than their own length apart ; septa moderately numerous, their edges with a slight, shallow 
forward waye in the middle of the periphery, (generally one septum coinciding with each tubercle, and one 
