Zoarium always adherent, rarely large.

Zoæcia pyriform when not crowded, small, the earlier forms larger than the later, but individually very variable; area sub-triangular; a slight internal front wall, occasionally surrounded by a faint line; under the oæcia the rim is very thin, very low, and set distinctly back from the general curve.

In view of the attention lately devoted by geological workers to the British Lower Carboniferous rocks and their fossils, an exhibit has been arranged in the Department of Geology at the Natural History Museum to illustrate the occurrence in the field of Corals in reference to the division of the Lower Carboniferous rocks into zones.

In the core of the Netherton Anticline at Saltwells, near Dudley, in the vicinity of a small area of basalt marked on the Geological Survey maps, Mr. King, in February last, discovered a series of rocks, ranging from the Upper Ludlow Mudstones to the Old Red Sandstone, cropping out from beneath the base of the Coal-measures of South Staffordshire. During April Mr. Lewis independently recognized Silurian here, and we agreed to work out the details together.

The Iguanodon, as is well known, was discovered by Mantell, who in 1825 named it from odd teeth which had a resemblance to the teeth of the recent Iguana. Many isolated teeth and bores were subsequently found in the Wealden and Lower Greensand beds to which the names of I. anglicum (F. Holl, 1829) and I. mantelli (H. yon Meyer, 1832) were given. It was not, however, until 1851, when Owen described an associated group of bones on a slab of sandstone from the Kentish Hag (Hythe Beds, Lower Greensand) of Maidstone, Kent, which had been discovered by W. H. Bensted in 1834, that the genus was to any extent known. This specimen has become the type of I. mantelli. In 1878 occurred the historic discovery of the skeletons of a number of Iguanodonsin the Wealden beds of Bernissart, near Mons, Belgium.

In re-arranging the large collection of Coal-measure fossils in the Manchester Museum I have had occasion to revise a number of species (notably in the Wild Collection) which have been recorded in the past under determinations which are now obsolete or erroneous. The object of this communication is to give a few critical remarks on these, as well as to place on record several hitherto unrecorded forms from the Lancashire Coal-field.