The third floor is as yet a large unfinished loft used for storage of the surplus stock of collections and for the fresh-water and alcohol tanks.

The building is supplied throughout with acetylene gas, heated by coal stoves, and amply lighted with triple casement windows with lower lights, 48 by 135 cm. The walls are of painted wood or plaster, and the floors are deadened throughout the building with sawdust.

The water supply, circulating system, and aquaria at the Kristineberg station have been worked out with great care. The water is at present drawn from the sea through a 3-inch galvanized-iron pipe, carried 20 m. from shore to a depth of 3 m. The pump house stands at the water's edge and contains a 4.6 horsepower petrol motor and a Lundberg iron pump. A 3-inch galvanized-iron pipe 68 m. in length carries the water to the detached water tower. This is a square wooden building (8.6 by 8.6 m.) on solid masonry foundations 3.5 m. high. The tower contains four large wooden tanks (2.6 m. in diameter and 3.1 m. in height) with a total capacity of 70 cu. m. From the tanks the water is carried to the laboratories in galvanizedpipes with brass valves.

The distributing system in the earlier building is of glass tubing inclosed in an outer tube of brass with a packing composed of a mixture of beeswax and turpentine between the tubes. The angles and connections are of brass heavily tinned, but the brass has begun to corrode in recent years. The new winter laboratory has a distributing system of galvanized-iron pipes with brass valves. The terminal outlets in both laboratories are of a special pattern constructed for the laboratory. They are made of ebonite and combine so many excellent qualities that they deserve to be widely used wherever the overhead spray method of aeration is employed in aquaria. They are tubes of ebonite designed for attachment to rubber tubing (Pl. LIV) and have a small opening in the tip which is removable for cleaning out bits of débris or other obstructions which often clog the fine terminals of a circulatory system. They are made both with and without a cock.

Four of the large aquaria in the new building are floor tanks (see Pl. LIII, A) with solid cement walls lined with glazed tile of white, blue, green, and gray colors. The large central floor tank is 1.78 (1.38 inside) m. square and has a depth of 58 cm. and a capacity of 1,104 liters. Its walls are 20 cm. in thickness. The smaller wall tanks are each 1.03 by 1.35 and 0.6 m. in depth with a capacity of 500 liters, walls 16 cm. in thickness. All have bottom flush pipe and overhead water supply. The two remaining large aquaria are elevated on masonry foundations to a height of 0.85 m. They are lined, respectively, with black and white glazed title. Each has a plate