Except in containing small nodules of phosphate of lime, the Chalk shows no structural change where it terminates in the Ely section, but passes down almost imperceptibly into a dark greenish layer, and rests on it at an angle of about 35°. This greenish band, scarcely a foot thick, is full of nodules of phosphate of lime, and consists largely of glauconite. It is the Upper Green-sand, with Ammonites auritus, Terebratula biplicata, Dentalium ellipticum, and the usual local features. Nowhere can the passage of one rock into another be more marked than that of the Upper Greensand of this district into the Chalk. Conditions have changed a little with physical geography, but nothing suggests any break in time. About Cambridge the section is exactly the same; the Chalk just above is often flaggy, contains a few green grains, a little phosphate of lime, and the commoner Greensand fossils mixed with those of the Chalk. Sometimes, however, there are some 10 or 12 feet of dark greyish-green marls above the Upper Greensand. They are separated by sharp lines of bedding from the Chalk, are very local, and perhaps only indicate a trifling denudation of the Gault.