Dr. Ayres read extracts from letters containing inquiries in regard to the first volume of the Proceedings of the Society, which terminated abruptly, and was never finished. The supply has long been exhausted, and the republication has been frequently discussed; but as yet this is beyond the means of the Society. Prof. Brewer communicated the following paper by Prof. Gray, giving the first installment of a series of descriptions of new plants from the botanical collections made by himself, while engaged in the State Geological Survey. These are a portion of the new species collected previous to 1863. The remainder will be described in future papers, along with those from the collection made after that time. Descriptions of New Californian Plants—No. I. BY PROF. ASA GRAY. STREPTANTHUS Nutt. _S. Breweri_, n. sp. [§ Euclisia.] Wholly glabrous and glaucous, annual, branched from near the base; cauline leaves (except the lowest) strongly cordate-clasping, with a closed sinus, entire or denticulate, the uppermost sagittate; flowers purple, on very short ascending pedicels, the lowest often leafy-bracted; the buds often a quarter of an inch long, obtuse, or barely acute; the sepals with scarious but blunt recurved tips; siliques narrowly linear, ascending or erect, straight or slightly incurved (1½-2½ inches long, less than a line wide,) compressed but torulose, the nerve of the valves obscure; seeds wholly marginless. This most resembles _S. tortuosus Kellogg_ (which is S. _cordatus Torr._, in _Bot. Pacif. R. R. Whipple’s Rep._ but evidently not of _Nuttall_), from which the above character indicates the differences. There are three forms in the collection: 1. A dwarf state, in flower only, from Mt. Shasta, at an altitude of 8,000 feet. 2. A very glaucous form, with more numerous and rather smaller flowers, and with fruit, from the top of a dry mountain of the Mt. Diablo Range, near head of Arroyo del Puerto, at an altitude of 3,200 feet. 3. Another, in flower and fruit, with more naked and virgate branches, a foot or two in height, from San Carlos Mountain, near New Idria, 5,000 feet altitude. This is remarkable for having the calyx hoary-downy, but the plant is otherwise glabrous and glaucous. _S. hispidus_, n. sp. (§ Euclisia.) Very dwarf, (2-3 inches high, from an annual root,) hispid throughout, even to the siliques; leaves cuneate or obovate-oblong, coarsely toothed or incised, the cauline-sessile but hardly at all clasping; raceme short and loosely flowered; pedicels spreading or at length recurved in flower (which is red or red-violet) but the linear compressed siliques (1½ inch long, a line wide,) are erect; stigma almost sessile; immature seeds winged. Mt. Diablo, dry places near summit. This ranks next to _S. heterophyllus_. VIOLA L.