Deep cuttings and long tunnels are regarded by railway-contractors as things to be avoided,though lessons of the greatest instruction are derived from them by the student of geology. But as safety in transit demands the easiest gradients, and a line as straight as possible, the lesser inequalities of the surface have often to be cut into, so that no insignificant part of geological teaching is derived from railway-work. And oft-times a way that puzzles the contractor to make “ good,” or a hill-slope that, lacking Knowledge of its springs, he has cut into only to see it slip continuously upon his line, are great aids and helps to comprehending the natural formation of a district, and so, a contractor's poison becomes a geologist's meat.

At the time of the commencement of Mr. Davidson's monograph on British Brachiopoda, published by the Palæontographical Society, little had been done towards their systematic arrangement and classification. Sowerby had figured many species; but valuable materials were accumulated, and many new forms waiting for description in the cabinets of different collectors, which have since been done justice to in the above valuable publication.

Shape not well defined in the specimens obtained. Ambulacral, areas wide; the two rows of pores in double pairs near the margin, with alternate additional perforated plates near the widest spread of the ambulacra; where these additional plates intervene the pores become quadruple; interambulacral areas wide.

The Protoechinos differs wholly from Palæchinus; and bears bat little affinity to any recent or fossil echinoderm with which I am acquainted.

The Sussex Marble, or Bethersden Marble, as it is indifferently termed according to its occurrence in Kent or Sussex, is found also in Surrey, near the foot of Leith Hill. It occurs in thin courses of variable thickness and extent, but seldom presenting a bed one foot thick, in the weald clay.