Page:The Botany of the Antarctic Voyage.djvu/150

128 This agrees with no other species of the genus in habit. It is allied to Dicranum filiforme, Schwaeg., but has entile teeth. The calyptra and operculum we have only seen detached amongst the leaves. There is a very similar plant in the Hookerian Herbarium, received from Mr. Dickson ; it has however a much longer seta, the perichaetial leaves are smaller and shorter, the cauline subsecund, more crisped when dry, and furnished with a thinner nerve.

Plate LVIII. Fig. III. — 1, a specimen of the natural size ; 2 and 3, leaves ; 4, periehatial leaf, seta, theea, &c. ; 5, teeth ; 6, calyptra : — magnified.

11. SPRUCEA Brid.

Peristomium simplex. Denies sedecim, bifidi. Calyptra ampla, glabcrrima, latere fissa, basi integerrima. — Holomitrium, Bridel. Endl. et Mart.fi. Bras. p. 17.

The generic name was founded on a mistaken view of the nature of the calyptra, described by Bridel as " elongato-conica, basi coarctata latereque integerrima ; " it is entire, in a very young state only, before the theca is developed. Hornschuch first modified the description of that organ, which is tridy dimidiate in all the species, though not as the last named author describes it, " campanulata." Except in greater size, it does not differ from that of TTeissia. The essential difference between a dimidiate and mitriforni calyptra arises simply from the former being too narrow to contain the mature theca, whilst the other is of sufficient capacity for that purpose. In habit this genus appears to us far less intimately allied to Racomitrium than to Bidymodon, with which it coincides in the dilated bases of the leaves; the chief peculiarities are the shorter teeth and longer operculum, characteristics which, if taken in conjunction with the large perichaetial leaves, may serve to keep the present distinct.

1. Speucea perichcetialis, Brid. ; caule erecto rainoso, foliis inibricatis erecto-patentibus lanceolatis acuminatis inargine planis, nervo continuo, periclisetialibus vaginantibus, theca oblonga, operciilo aciculari. Holomitrium perichartiale, Brid. Bri/ol. Univ. vol. i. p. 227. Trichostomum, Hook. Muse. Exot. t. 73.

Hab. Campbell's Island ; not uncommon on the stems of shrubs.

In this species the teeth are split near the summit only, perforated below, and of a similar structure with those of a Bryplodon, Brid.

12. DICRANUM, Hedw.

Peristomium simplex ; dentibus sedecim, bifidis. Calyptra cuciuliforniis.

1 . Dicranum Memiesii, Tayl. ; caule ascendente subrarnoso, foliis secundis setaceis basi lanceolatis subrigidis apice sub lente scrrulatis siccitate strictis nervo latiusculo valido subexcurrente, seta brevi, theca elliptico-oblonga basi substrumosa semiimmersa, operculo longirostro. D. Menziesii, Taj/lor in Phytologist, vol. ii. p. 1094.

Hab. Lord Auckland's group; on trunks of trees sparingly, barren. Caules semiunciales. Folia suberecta, conferta, 3-5 lin. longa, valde angusta, supra canaliculata, flavescentia, marginibus basi inflexis ; perichatialia vaginantia - breviora, basi dilatata. Seta 3 lin. longa, pallida, vix tortilis.