374 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [ Mar. 9, 
Nive ( ft-sins, ftaans 
was obtained the remarkable new starfish, Sted/aster Sharpii, 
Wright *, also Astarte minimus in clusters, Rhynchonella variabilis, 
Ler eDr aula perouanespeNOVOTACS SLC: satchel. este see aeaee Renee 16 
7. Ironstone containing plants, Acrosalenia, KC. .1..csecceceeeeceenceseues 1g) 
8. ‘“ Sand-bed ”—coarsely cellular ironstone, with sandy cores—some- 
times hard sandstone—containing few fossils ...............06.06 TG 
9. “ Four-foot bed’”—cellular ironstone, with ochreous and argilla- 
ceous cores, in many layers and very crumbling, alternating fre- 
quently with irregular arenaceous bands, sometimes 2 feet in thick- 
ness, and exceedingly fossiliferous—Hinnites abjectus, Pecten, 
Ammonites, Rhynchonella, SC. sicscecececscecvececsevenceeecnceens 40to6 O 
10. Variable beds, with very green cores, oxidized on the joint and 
bedding planes, in thinner bands at the top and towards the bottom, 
occasionally very rich in fossils, the tests sometimes preserved— 
Coral, Lima (various species), Pecten articulatus, wood, &c. Of the 
larger blocks, the iron-ore coating only is used for smelting 8 0to9 O 
11. Much broken ferruginous beds, not worked because of water, and 
little known: a zone at bottom, exposed in the section of a neigh- 
bouring clay-pit, is probably equivalent to the Ammonites-bifrons 
zone, the bottom bed of Bass’s pit. I have an example of A. Ji- 
frons said to have been obtained from this pit, but upon doubtful 
authority. The lowest zone contains numerous rounded pebbles 
or concretionary nodules...............:.0s0+-+ Bee neice slotieesuaas about 3 
12. Band of mixed material, as at Kingsthorpe brick-pit .................. 
Upper Lias Clay. 
lori) 
Although I have associated in this section certain beds with 
certain fossils generally found in them, yet this association must not 
be understood to amount to a limitation. The more abundant 
fossils, such as Cardium cognatum, Isocardia cordata and a large 
new species, Ceromya bajociana, Lima (various species), Cucullea 
(various species), Macrodon hirsonensis, Trigonia (various species), 
Pecten demissus, P. lens, and some other forms, are found almost 
indifferently, but irregularly, in all the beds of the section. 
A certain significance, however (to which I have already alluded), 
attaches to the position in this section of the zone of Astarte elegans, 
having immediately above it a bed containing Ammonites Murchi- 
sone and Pholadomya fidicula. It will be remembered that a similar 
zone occurs in the Old Duston, Old Slate Quarry, and Harlestone stone- 
pits (wv, v, and v’), marked by the presence of the same Ammonite and » 
bivalve—and also in the wells near Hopping Hill, at about the 
same distance from the surface as in the Old Duston pit. The 
occurrence of such a zone at these five different points, thus marked 
at two of them by the presence of Ammonites Murchisone and Pho- 
ladomya fidicula, would seem to point to the conclusion that it 
represents an horizon within this area, and to the equivalence within 
the same area of the beds (at whatever points found) lying between 
this zone and the Upper Lias Clay, especially as the thickness of the 
ferruginous beds penetrated by the wells (near y) is more than 
equal to the entire thickness of the Old Duston pit section down to 
the Astarte zone added to the thickness of the Duston ironstone pit 
section from the Astarte zone down to the Upper Lias clay,—that is, 
* Vide Note by Dr. Thomas Wright, F.R.S.E., F.G.S., appended to this 
Memoir. 
