Our stay in the Bay of St. Francisco, in California, during the months of October and November, was unfavourable to the observations of a naturalist. A perfect drought prevails during those months; vegetation appears completely dead; and all birds of passage abandon the country. The landscape along the coast is alternately formed of naked hills, of a rocky or clayey soil, and low sandy levels, covered with stunted bushes. Further inland, the soil is more fertile, but still deficient in wood. The background every where presents lofty mountains; we visited only those to the north, at the foot of which the Russian settlement Ross is situated. Here a fine forest of lofty pines, mingled with oak and horse chesnut-trees, charms the eye. Of the mammalia of this hitherto unexplored country, only a few can be cited. The light grey American bear, with a small head, abounds in unfrequented districts, but brown bears are also occasionally killed. We nearly ascertained the existence of two sorts of polecats, and succeeded in getting a skin of one; its fur is brown below, and black above: from the forehead a white stripe runs to the middle of the back, and then divides into two, which extend to the extremity of the tail. The feet of the animal show that it treads upon its entire sole, and lives in holes like a badger. The second sort is said to have three white stripes: our sailors caught one, but it got away again. The mole here is larger than in Europe; the upper part of the body is of a greyish brown, the lower part an ash grey; the legs are covered with a white fur, and the taper tail is one-fifth of the length of the body. A shrew-mouse also was caught. Two or three kinds of large cats are said to have been seen; a _mustela_, something of the nature of the _Lutreola_, was shot near the Rio Sacramento. The sea-otter still abounds here, but its hair is brownish, and not black. The _Cervus Wapiti_ is found in great numbers in hilly districts; and there are deer in all unfrequented places. The back and sides of the latter are of a reddish brown in summer, in winter of a blackish brown; the belly, breast, and inside of the legs are white; the mouth, forehead, and the exterior of the ears are black. The antlers (of the male) divide into a fork, with round smooth branches. The animal grows to the height of two feet and a half. Near the Rio Sacramento, and in the vicinity of the Russian settlement, we saw herds of animals of the shape of goats, with long hair hanging from their legs, and short straight horns; we were unfortunately unable to obtain a specimen; we saw the animal only through a telescope, and judged it to be the _Capra Columbiana_, or _Rupicapra Americana Blainville_, so often spoken of. Lastly, we have to mention a small kind of hare, not so large as a rabbit, found in great abundance among the bushes, and a dormouse seen in the southern plains.