Height, five to twenty feet, but the greater number averaged only from five to fifteen feet. Only one tree which I noticed which was fifty-five inches in circumference, and twenty to twenty-five feet in height. It had a flattish top with the branches very much imbricated and so completely covered with cones, that it was really difficult to discover its foliage. But this tree was very exceptional, compared with the mass of little trees covering the plains. These had in general upright branches with numerous and slender branchlets; leaves shorter, denser, and of a darker green than _Pinus contorta_? which grows with it and is a larger tree altogether; bark reddish, very thin, exhaling a strong resinous odor, and but slightly rimose; cones two to four inches long (curved when long) and scarcely an inch thick, mostly in pairs, but sometimes in threes, reflexed. I counted fifteen sets of cones on a tree fifteen feet high. 7. _Pinus contorta_, Dougl.? Head of Tomales Bay! Mendocino City! Its manner of growth resembles that of _Pinus insignis_ very much. It attains the same height, has the same irregular spreading branches, the same thick rimose bark and very resinous wood. The leaves are invariably in pairs and slightly silvery on the lower surface. The cones are scarcely two inches long with mostly reflex pedicles (umbo) on the slightly gibbous side and persistent for a great number of years. From the River Albin to Mendocino City, it grows quite near the coast on a fertile and undulating plain, gently descending towards the ocean. At Mendocino City I found it to extend all over the plains about eight miles eastward. Whether this species is identical with _Pinus contorta_ or not I am unable to decide. Observations made by Mr. Geo. Wm. Dunn, on his recent travels through the Blue and Siskiyou mountains, have rather a tendency to show that _Pinus contorta_ is altogether a different tree. I can state, however, most positively that this species cannot be confounded with _Pinus muricata_. Both species are two-leaved, but in every other respect they differ widely. The object of these remarks is only to point out the different species, met in my travels, and not to decide which name should have precedence. Murray’s discussion on the distribution of our Pines, in his “Notes on California Trees,” has not “struck” me as being so very correct. Endlicher, in his Synopsis Coniferarum, makes _Pinus muricata_ a Taeda, which is also incorrect; it is a true Pinaster. It remains to decide only, whether the species at Mendocino City is _P. contorta_, or _P. Murrayana_, Balf. 8. _Libocedrus decurrens_, Torr. (California White Cedar.)