The Little Island of Trinidad, as it is called to distinguish it from the larger island in the West Indies, is situated in the South Atlantic Ocean, about 700 miles off the coast of Brazil, in lat. 20°31' S. and long. 29°19' W.

According to Ross, who in 1839 effeeted a landing on tile N.W. coast, the island is a mass of volcanic matter, the rocks of which it is composed assuming the most extraordinary shapes. The most remarkable of these are the Sugar Loaf Hill on the southern and the Nine-Pin Rock on the north-western coast.

During a recent visit to Cornwall the attention of Professor Lewis was directed by Mr. James Wickctt to some composite crystals of copper pyrites recently found in one of the deep mines in the neighbourhood of Redruth. On the specimens acquired by the Cambridge Museum about thirty crystals show this composite growth, which causes the crystals to resemble ill-developed pentagonal dodecahedra of iron pyrites.

Grassmann, in his Memoir, Zur physlschen Krystallographie und geometrischen Combinationslehre, published in 1829, referred a crystal to three face-normals--rays--as axes of reference; the parameters being the edges along the axes of a parallelepiped having for diagonal a definite length of a known normal which is not co-planar with any pair of the axial rays. Any other normal is then represented as the diagonal of a similarly formed parallelepiped having for its edges along the axes lengths which are rational multiples of the parameters. Grassmann gave no formulæ for finding in general the indices of face-normals from measurements of the angles on the crystal; nor for determining the angles from the crystal-elements and indices.

Take three axes of reference OX, OY, OZ mutually at right angles. A convention must be made as to the positive direction of rotation about any line, and that usually adopted is as follows. A positive rotation about OX rotates OY towards OZ, one about OY rotates OZ towards OX, and one about OZ rotates OX towards OY. To find the positive direction of rotation for any line ON we must suppose ON moved to coincide with one of the axes, say OZ, and then apply the preceding rule.

The stones to which this paper refers were sent to Prof. Miers for determination by Mr. Francis Powell, and were stated to come " from the diamond washings." They are of a fine green colour, and quite transparent, and possess a highly perfect cleavage parallel to the faces of a prism having an angle of about 88°. This serves to distinguish the material from olivine, which it otherwise much resembles, and --coupled with the uniformly straight extinction through cleavage flakes, the specific gravity (3.199) and hardness (6-7)--suffices to identify the mineral as one of the rhombic pyroxenes.

In the course of an investigation on calcareous secretions in the animal kingdom, and more particularly on molluscan shells, I found that the latter did not consist of aragonite, as G. Rose and Sorby had supposed, but of a negative, uniaxial mineral, which is distinguished by most of its properties from calcite, and for which I propose the name conchite (KóγXη, shell). I further found that conehite occurred naturally in many localities--always as a crystal aggregate. Its properties were investigated on such, as well as on the eonchite in shells.

It has for many years been proposed to form a reservoir with an area of some 36 square kilometres for irrigation purposes near Hiriyur in Northern Mysore, by erecting a dam at Marikanave, where the River Vedavati or Hagari crosses a rocky ridge running north-north-west and south-south-east.

Doubts were raised as to whether the rock would form a sufficiently firm foundation, but Mr. Robert Bruce Foote, late Superintendent of the Geological Survey of India, and my predecessor as State Geologist in Mysore, reported that it was in every way suitable for the purpose.

Since the publication, three years ago, of the ficst of these lists at the end of Volume XI of the Minertdogical Magazine, so many new mineral names have been given that a second list may be useful as a completion to Volume XII. In addition to names which have recently been published are a few earlier names which are not to be found in some of the larger works of reference. The numerous compounded chemical and mineral names for artificial substances prepared by Doelter, Lemberg, Thugutt and others, have, with one or two exceptions, been omitted.