On the Pacific coast such distinct lines of demarcation do not exist, there being no such natural barriers as are formed on the eastern coast, first by Cape Cod, and, second, by the stretch of sand-beach which extends from New York to Charleston, and which divides sharply the climatic varieties. The whole shore is again divided laterally into three distinct belts, called the /littoral/, the /laminarian/, and the /coralline/ zones. The first or littoral zone covers the space between tide-marks. Vegetable life in this zone is subjected first to exposure to the sun and air, and even to desiccation, and then to entire submergence at constantly recurring periods. The rockweeds (/Fucus/), which are so plentiful in this zone, are very gelatinous, nature having apparently provided the gelatine to protect the cells of the plant from the effects of the alternating extreme conditions. /Fucus/ and /Enteromorpha/ predominate in this zone. [pg031] The laminarian zone extends from low-water mark to the depth of fifteen fathoms. The /Laminariaceæ/ and the beautiful red algæ (/Florideæ/) grow here. The third or coralline zone extends to the depth of about fifty fathoms. The algæ of this zone, the nullipores, are incrusted with a deposit of lime which gives them the appearance of corals; and, singularly enough, the corals, which are animal forms, simulate plant life. Again, algæ have special habits and demand certain climates and seasons for their growth. Algologists register the place where a specimen is found, and in this way localities have been pretty well determined. However, great exactness has not been reached, and the collector is ever watchful to find an alga in some undiscovered home within the given range. Although algæ grow from extreme high-water mark to the depth of fifty fathoms, almost every variety may be found on the beach, those growing in deep water being frequently torn off and washed ashore by the waves. The heaps of sea-wrack will often reward one who examines them carefully for deep-water species. Seaweeds are most abundant on rocky shores, particularly where there are stratified rocks with crevices, which afford shelter from the waves. Rock pools often contain beautiful varieties of the more delicate species. Red algæ will sometimes be found on the shady side of these pools. Sand-beaches are unfavorable to the growth of seaweeds, but fronds which have been carried long distances by the currents will frequently be found on such shores. [pg032] IX SOME PECULIAR AND INTERESTING VARIETIES OF ALGÆ