ture, serving frequently to discriminate species. See Engl. Bot. t. 1037—9, 1182, t. 1445—8, &c.; see also the same part in Neckera, t. 1443, 4. Linnæus apears by his manuscripts to have intended adding this to the different kinds of calyx, though it is not one of the seven enumerated in his printed works. Nor is he, surely, correct in allowing it to the genus Jungermannia. The membranous part which he there calls perichætium is strictly analogous indeed to the calyptra or veil of real mosses, esteemed by him a kind of calyx; but as I presume with Schreber to reckon it rather a corolla, and Hedwig once thought the same, and as Jungermannia has more or less of a real calyx besides, see Engl. Bot. t. 771, &c., I would no longer apply the term perichætium to this genus at all.
The part called calyptra being removed from the list, as being a corolla, the perichætium takes its place among the seven kinds of calyx. We lay less stress upon this coincidence than Linnæus might have done, when, according to the fashion of the times, he condescended to distribute
