24 REPORT—1874., 
meridge Clay. Between 950 feet and 972 feet we have no good palewonto- 
logical evidence. The fossils which occur here are the following :— 
Avicula. 952 feet. Ostrea. 953, 965 feet. 
Cardium striatulum. 951, 952 feet. Pecten arcuatus, Sow. 952 feet. 
C. striatulum, yar. lepidum, Sauwv. e¢ Rig. Astarte (a smooth species). 956 feet. 
967 feet. Thracia depressa. 966 feet. 
Nucula. 951, 952 feet. Ammonites biplex? 957, 969 feet. 
Lingula, resembling L. ovalis, Sow. Tornatella. 967 feet. 
. All of these (excepting perhaps Tornatella) occur in the Kimmeridge Clay. 
Thracia depressa is very characteristic of the Kimmeridge Clay, but it also 
ranges downwards to the Great Oolite. It occurs at 965 feet in a soft dark 
clay, which ranges with much the same characters from 963 feet to 976 feet ; 
and as it is this clay which (at 972 feet) contains Ammonites Sedgwick, we 
can hardly take a boundary at this point. Above this there are 5 feet of 
unfossiliferous sandy clay, and then come 8 inches of hard, dark grey, heavy, 
and sandy clay, with much petroleum. Just above this there is a little hard 
sandy clay, containing a layer of a smooth form of Astarte, and above that 
some soft dark clay. 
If we have to fix upon a definite line, it would probably be advisable to take 
it just below the soft clay last named, at 956 feet. One reason for doing this 
is, that at 965 and 972 feet there are sometimes well-marked signs of a dip 
across the bore-hole ; sometimes this is shown by the layers of fossils lying 
obliquely ; and at 965 feet it was very distinctly shown by a layer, 1 inch 
thick, of light-coloured clay; the dip of this was about 10°. 
The dips in these places are not owing to an unconformity, because the 
layers of fossils just above and just below are quite horizontal. But nothing 
of the sort has been observed in the true Kimmeridge Clay ; and this is one 
reason, though a very slight and untrustworthy one, for taking the boun- 
dary above these beds. Higher up in the Kimmeridge Clay there have been 
cores breaking obliquely, which at first look like inclined strata; but in all 
such cases careful examination has shown that these appearances are due to 
thin veins of carbonate of lime. 
It was stated above that Gryphea virgula is solely a Kimmeridge-Clay’shell. 
In Damon’s ‘ Geology of Weymouth’ it is stated that this shell occurs in 
the Oxford Clay of that district; but in the Atlas of Plates which accompa- 
nies the Handbook, a figure is given as Gryphwa (Ostrea) virgula, which is 
certainly not that shell, nor one in any way resembling it. We must therefore 
conclude that the true Gryphca virgula has not yet been found in the Oxford 
Clay of Weymouth. 
In the Sixth and Seventh Quarterly Reports, Modiolu pectinata, Sow., appears 
amongst the lists of fossils. Further examination of these shells has shown 
that, although they resemble the shell figured under that name in Phillips’s 
‘Geology of Oxford,’ they are really distinct from the shell figured by Sowerby. 
Sowerby’s shell is really a Mytilus, and as such he described it (Mytilus 
pectinatus); whilst the shells of the boring are certainly Modiole. They. 
somewhat resemble the Mytilus Morris: of Sharpe, originally figured from 
specimens from the Sub-Cretaceous limestone of Portugal, but which also occurs 
in the Kimmeridge Clay of Wootton Bassett and in the Boulonnais., They are, 
however, distinct from this, and must be regarded as a new species. In 
the Museum of Practical Geology there is an unnamed specimen of this 
species from the Kimmeridge Clay of Hartwell. 
Dr. Lycett has kindly examined some specimens of 7Z'rigonia from the 
boring. Amongst them he recognized a young form of Trigonia Juddiana, 
