84 THE JOURNAL OF BOTANY 



without, like a wide hyaline border to the (apparent) base of the 

 papillose, orange tooth. The outer walls of these hyaline cells not 

 being thickened or coloured, there is therefore no dorsal layer to 

 the peristome as in S. Boivini, the whole of the coloured portion of 

 the teeth being derived from the innermost walls; moreover, each 

 tooth being faced (at any rate in the upper part of the concealed 

 portion) by only a single cell, from the inner wall of which it is 

 derived by thickening, it is not divided by any median line, the ex- 

 serted portion consisting of a narrow linear single row of plates. 

 This constitutes a marked difference in the structure of the teeth 

 from those of S. Boivini, S. Baileyi, and perhaps most species of 

 the genus. The lowest portion of each tooth near its insertion is, 

 however, usually composed of two rows of plates, passing into a 

 single row before reaching the orifice of the capsule. 



The effect of the large hyaline uppermost cells of the third layer 

 is to constitute a form of pre-peristome, consisting of a hyaline ring 

 of cells usually just appearing above the rim of the capsule, and 

 resembling at first sight a ring of persistent annular cells, from 

 which, however, they differ in the apex of each (dorsal view) being 

 truncate, instead of rounded, and of course their origin is entirely 

 different. They may, I think, fairly be described as a pre-peristome 

 being very nearly homologous with that structure as it appears in 

 certain species of Orthotrichum ; the principal difference being that 

 there it is formed from the thickened and coloured portion of the 

 outer walls only of a layer of cells, while here it is formed from the 

 whole of the cell, the walls being unthickened and uncoloured. 



The following is a diagnosis of the species : 

 Splachnobryum delicatulum Broth, in Utt., sp.nov. Dioicum. 



Pusillutn. Caespites densi, saturate virides. Caulis tenellus, 3- 

 8 mm. altus, simplex vel parce ramosus, densiuscule foliosus. 

 Folia mollia, patentia, apice saepius leniter patulo-recurvo, concavi 



i 



uscula, ovata vel oblongo-subspathulata, apice rotundato obtusa, 

 0*6-1 mm. longa, margine plus minus reflexo, nonnunquam piano, 

 integro vel apice tantum vix crenulato, nervo tenui sub apice 

 evanido ssepe rubello, rete valde laxo, parietibus tennibm, chloro- 

 phylloso, cellulis pro more magnis, irregnU titer hexayono-rhomboidtis, 



elongatis, 40-65 /* longis X 12-16 p latis, basin versus hyalinis, 

 elongato-rectangularibus, magnis, prope apicem solum breviusculis, 

 ad marginem superiorem seriebus singulis sub-quadratis. Fl. $ 

 terminales, nonnunquam laterales, gemmiformes, antheridiis pro 

 more magnis, conspicuis. Fl. ? terminales, saepe quidem et 

 laterales (plerumque archegoniis nudis singulis in foliorum axilhs 

 per totum caulem instructis). Seta e vaginula elongata teiuus, 

 2-5-3 mm. longa, rubra; theca angusta cylindrica minnta, 0'5 mifl- 

 longa, operculo conico-rostellato ; 

 rubro oriundi, angusti, linea __, 



aurantiaci, inter se raro coh*erentes. Ante uuumquemque denteni 

 ad inferiorem partem singular cellularum series, quarum ultimo 

 magna hyalina supra thecae os paullo exserta, praperistomiuw 

 sistentes, inveniuntur. Sporae 12-16 p, laeves. 



to ; peristomii dentes longe sub ore 



res, nee linea media divisi, papillose 



