740 PROF. J. W. JUDD ON THE NATURE AND RELATIONS OF 
situ at no great distance; but this question will be discussed more 
fully in a subsequent portion of the present paper. 
The 10 ft. of remarkable strata which intervene between the base of 
the Gault and the Great-Oolite beds, about to be described, offer 
some very interesting, and at the same time difficult, problems to the 
geologist. They seem to have been formed to a great extent of 
materials derived from the subjacent rocks, some of the fragments of 
which had been subjected to much attrition. The presence of phos- 
phatic nodules probably indicates the lapse of a considerable interval 
of time, during which sedimentation was suspended. The foreign 
fragments included in them, some of which are only rounded on 
their edges, suggest the proximity of land made up of the rocks in 
question. 
The problem of the age of this 10 ft. thickness of beds is one 
which it is not easy to solve. The limestones contain a few 
oysters, having the appearance of being dwarfed from the unfayour- 
able conditions of brackish water. They greatly resemble the 
small oysters found in the Punfield series, which I have elsewhere 
shown to be the dwarfed condition of Kxogyra sinuata* ; but the 
dwarfed forms of many species of the Ostreide are so similar to one 
another, that it is impossible to speak with any confidence con- 
cerning the geological age of these fossils. 
The only other fossils, not manifestly derived, which I obtained 
from these beds were the microscopic Ostracoda and Foraminifera ; 
these have been examined by Prof. T. Rupert Jones, F.R.S., and 
referred to the following species :— 
Ostracoda. 
Cythere subconcentrica, sp. n. 
juglandica, sp. n. 
Cytheridea subperforata, sp. n. 
Cytherella symmetrica, sp. n. 
Bairdia Juddiana, sp. n. 
trigonalis, sp. n. 
Foraminifera. 
Cristellaria italica, Defr. Cristellaria rotulata, Lam. 
Cristellaria, sp. 
Prof. Jones says of these forms that while some may be of any 
Secondary or Tertiary age, others, like Cythere concentra and 
C. virginea, have Cretaceous allies or representatives. 
Although it must be confessed that the 10 ft. of strata under- 
lying the Gault at Richmond may be cf any age between that of 
the Great Oolite and that of the Gault, yet I think that, taking all 
the facts into consideration, they may be most probably referred 
to some part of the Neocomian period. 
In their nature and relations, though not in their age, these beds 
present some analogies with the “ Tourtia,” which in Belgium is so 
frequently found separating the rocks of the Paleozoic ridge from 
the overlying Upper Cretaceous strata. 
* Quart. Journ. Geol. Soc. vol. xxvii. (1871), p. 214. 
