The best time to collect is when the tide has just commenced to flow, after the lowest ebb, as the sea weeds are then floated in, in good condition. All specimens should be either red, green, purple, black, or olive; no others are worth preservation.

Mounting is done by immersing a piece of paper just below the surface of the water, and supporting it by the left hand; the weed is then placed on the paper and kept in its place by the left thumb, while the right hand is employed in spreading out the branches with a bone knitting-needle or a camel's-hair pencil. If the branches are too numerous, which will be readily ascertained by lifting the specimen out of the water for a moment, pruning sbould be freely resorted to, by cutting off erect and alternate branches, by means of a sharp-pointed pair of scissors, close to their junction with the main stem. When the specimen is laid out, the paper should be raised gradually in a slightly sloping direction, care being taken to prevent the branches from running together. The delicate species are much improved in appearance by reimmersing their extremities before entirely withdrawing them from the water. The papers should then be laid flat upon coarse bibulous paper, only long enough to absorb superfluous moisture. If placed in an oblique direction, the branches are liable to run together. They should be then removed and placed upon a sheet of thick white blotting-paper, and a piece of washed and piressed calico placed over each specimen, and then another layer of thin blotting-paper above the calico. Several of these layers are pressed in the ordinary way, light pressure only being used at first. The papers, but not the calico, may be removed in six hours, and afterward changed every 24 hours until dry. If the calico be not washed, it frequently adheres to the alga», and if the calico be wrinkled it produces corresponding marks on the paper. The most convenient sizes of paper to use arc those made by cutting a sheet of paper, of demy size, into 16, 12, or 4 equal pieces. Ordinary drawing-paper answers the purpose very well. For the herbarium, each species should be mounted on a separate sheet of demy or cartridge size. Toned paper shows off the specimens well, a neutral tint answering best for the olive, pink for the red, and green for the green series.