ODLING : CORRELATIOX OF THE UPPER AND MIDDLE OOLITES 273 
this noticeable in the Supra-Corallian beds in the Weymouth districts 
where the alternation of Corallian and Kimeridgean faunas is well 
marked. Before the beds were examined by Dr. Hans Salfeld* in 
reference to Ammonite zones, the i\.bbotsbury Iron Ore, for instance, 
was always considered as the highest bed of the Corallian ; it is now 
seen, however, that this bed occurs high up in the Kimeridge Clay, 
and that the Corallian facies of its fauna is due to local conditions. 
In this country the term " Corallian " is of such stratigraphical 
importance that its abolition would be most undesirable, yet when 
dealing with an area of Continental magnitude its abolition has much 
to recommend it. Similarly, as Dr. Strahan remarks, f the terms 
" Oxfordian," " Kimeridgian " and Portlandian," associated as 
they are with definite districts, convey to us a very definite meaning, 
but they have been adopted in quite a distinct sense on the 
Continent. For this reason the terms Upper " and Middle 
Oolites," though inappropriate to argillaceous deposits, would be far 
more desirable. 
The zones generally recognised in this country may be seen in 
Plate XXVIII. and are for the most part generally recognizable over 
the country ; the zones, suggested by Dr. Salfeld.J which are based en- 
tirely on Ammonites, are of considerable palseontological interest, but 
the unfamiliarity to British geologists of a number of the zonal indices 
and the adoption of a number of new genera and species render it very 
difficult to correlate his zones with those more generally known. A 
zonal table based on other groups — as has been done by the late 
Dr. Vaughan in the Avonian — placed at the side would have con- 
siderably increased the value of Dr. Salfeld's paper. 
Shortly before his death, Blake commenced a monograph on the 
Fauna of the Cornbrash,§ with a view to shewing that it was more 
intimately linked with the beds above than with the beds below ; 
unfortunately, owing to his untimely death, the part dealing with the 
Pelecypods, on which most of his conclusions were based, was never 
published. 
* Quart. Journ. Geol. Soc, Vol. LXIX., p. 423 et seq. 
t Quart. Journ. Geol. Soc, Vol. LXIX., p. 432. 
J Ibid., p. 423 et seq. See also fig. 2. 
§ Palgeontol. Soc. Monograph, Fauna of the Cornbrask. 
