The first account of tbe geology of Socotra we owe to Lieutenant J. R. Wellsted, who compiled the Admiralty chart and map, and in 1835 described the island in a detailed memoir, in which he showed that it consists of a mass of granite capped by limestones. Nothing material was added to this description until 1883, when Professor Bonney published his account of the extensive rock collection made by Professor J. B. Balfour during a six weeks' visit to the island in February and March, 1879. Professor Bonney's study of the rock specimens enables him to prove that Socotra consists of a block of Archean rocks covered in places by massive limestones, which, on the evidence of their foraminifera, Professor T. R. Jones suggested were probably of Miocene age

In many places in Western Norway we find a lake separated from a fjord by a mile or so of sand and gravel. Looking from the fjord, we see in such a case a series of step terraces, with possibly a high mound at the back, forming a dam at the end of the lake.

By correlating the head and the tail of Professor G. P. Merrill's “Discussion on the use of the terms Rock-weathering, Serpentinization, and Hydrometaraorphism,” I infer a direct invitation to confer with him on the questions raised by me at the Bristol meeting of the British Association.

Amongst the hosts of Antelopes, Rhinoceroses, Hipparions, etc., which form the bulk of the Pikermi fauna described in Gaudry's classical “Animaux Fossiles et Géologie de l'Attique,” the mandible of Leptodon græcus, with lower molars recalling the Palæotheres and Paloplotheres, seemed to stand out, as it were, as an anachronism. It has always appeared to me, as it may also have to others, that the occurrence of such a type in the above company (with which Orycteropus and the Ostrich are also associated, in the contemporary beds of Samos) might be accounted for in a satisfactory manner, if Leptodon could be shown to be related to the Hyraces.

In his work entitled “Die Versteinerungen Würtembergs” C. H. v. Zieten figured and briefly described a species under the name Ammonites calcar. The description is as follows:“Rücken gewölbt, Rückenlinie spornradförmig gezackt; er hat in dem Baa seiner Rippen und dem erhöhten Saum seiner Windungen grosse Aehnlichkeit mit dem vorhergehenden [i.e. Ammonites bipartitus, Zieten], unterscheidet sich jedoch von ihm sogleich durch seine einfach gezackte Rückenlinie. Aus dem untern Oolith bei Guttenberg.”

The delay of several months, in replying to Mr. Hudleston's communication relative to the above-named subject, has been due to absence in the field in a distant region, where I was not in touch with the current literature.