1. An attempt is made to indicate the quantitative distribution of the Crustaceans inhabiting certain Scottish intertidal areas.

2. Certain areas in the Clyde, notably Cumbrae, show a rich Amphipodan fauna which exhibits zoning by species.

3. Bathyporeia guilliarnsoniana is the dominant amphipod on the Tellina-Nephthys grounds (clean sand) and Corophium volutator is indicative of a muddy to brackish environment.

1. A general method for the solution of differential equations by definite integrals has recently been given by Professor E. T. Whittaker. It is briefly that, if a contact transformation from variables (q, p) to (Q, P) be given by Q = Q(q, p), P = P(q, p), and if this transforms an expression G(Q, P) into F(q, p), then the solutions of the differential equations

are connected by a relation of the form

The X-ray examination of d-mannitol and d-mannose gives the following results:—

d-Mannitol.—Unit cell, a = 8·66 A.U., b = 16·58 A.U., c = 5·501 A.U.; Space-group, Q4; Calculated density, 1·522 grms. per c.c.; Number of molecules per unit cell, 4.

The X-ray data show that the greatest length of the molecule corresponds to the a axis, and that the molecules have a long chain configuration.

d-Mannose.—Unit cell, a = 5·53 A.U., b = 17·66 A.U., c = 7·59 A.U.; Space-group, Q4; Calculated density, 1·602 grms. per c.c; Number of molecules per unit cell, 4.

The X-ray results show that a manno-pyranose ring structure is probable in the d-mannose molecule, and that the molecule has its greatest length along the c axis.