^46 



SYSTEMATIC HISTOEY OF THE INFUSOEIA. 



not tapering^ inflation obsolete, ends en- 

 tire, surface all over minutely spinous, or 

 Mrsute. U.S.A. 



Kiitzing (Sp. Alg.) describes one or 



two other species of Docidium ; but the 

 characters given seem hardly distinctive, 

 and appear sometimes more like generic 

 characters re-stated. 



Genus TETMEMORUS (Ralfs).— Frond elongate, Btraight, cyHndiical or 

 fusiform, constricted at the middle ; segments more or less tapering, not in- 

 flated at the base, ends with an acute incision, the subdivisions rounded, 

 otherwise quite entire. 



Tetimemobus Brehissonii (Ralfs). — 

 Frond about five or six times longer 

 than broad ; in f. v. tcith parallel sides, 

 the constriction a very shallow groove ; 

 in s. V. fusiform, the constriction very 

 slightly deeper ; endochrome with a lon- 

 gitudinal series of light-coloured large 

 granules ; e. f. punctate, the puncta in 

 longitudinal rows. L. 1-142" ; B. 1-704". 

 (ii! 12 & 13.) = Closterium Brehissonii 

 (Menegh.), Penium monile (Kg.); P- ^^^'*'- 

 ato-punctatum (Kg.) ? G.B., I., F., G., 

 Italy, U.S.A. /3, turgidus,lsiVgeY, stouter, 



constriction deeper, y, (De Bary), 



smaller than either, otherwise externally 

 similar, endochrome in longitudinal 

 fiUets. 



broadly elliptic ; in s. v. compressed, 

 enclosed in a central cell placed between 

 the ultimately deciduous emptv fronds. 

 L. 1-374" to 1-336"; B. 1-1244" to 

 1-1073". = Penium (Tetmemorus) Bre- 

 bissonii (Kg.). G.B., I., F., G. 



T. 7ninutus (De Bary). — Frond minute, 

 shorter than T. Iceris, about three times 

 longer than broad, fusiform, the con- 

 striction a very shallow gi'oove ; e. f. 

 without puncta. L. 1-41"'; B. 1-118"'. G. 



T. granulatus (Ralfs). — Frond some- 

 what longer than T. Brehissonii, about 

 five or six times longer than broad ; m 

 both f V. and s. v. fusiform, the constric- 

 tion a very shallow groove, ends tcith a 

 hyaline lip-like projection extending be- 



T. Icevis (Ralfs). — Frond smaller than yond the notch ; endochrome vdth a 



last, scarcely one-half its length, about 

 three or fom- times as long as broad; 

 in f V. somewhat tapering, the constric- 

 tion a shallow depression -, in s. v. fusi- 

 form; end sometimes with a hyaline 

 lip-like projection extending beyond the 

 notch ; e. f! punctate, puncta faint but 

 evident, scattered. Sporangium smooth, 

 in f. V. at first quadrate, afterwards 



longitudinal series of large granules: 

 e. f. punctate, the puncta scattered, ex- 

 cept near the constriction, where they 

 are disposed in two transverse rows. 

 Sporangium orbicular, smooth, margin 

 finely striated, placed between the de- 

 ciduous empty fronds. L. 1-130"; B. 

 1-Q4Q".= Penium (T.) grantdatus (Kg.). 

 G.B., I., F., G., Italy, U.S.A. 



Genus CLOSTERIUM (Nitzsch). — Frond elongate, attenuate, more or less 

 Innately curved or arcuate, entire, not constricted at the middle, the junction 

 of the segments marked by a pale transverse band. Endochi'ome often 

 arranged in longitudinal fillets, and at each extremity having a terminal clear 

 space, in which are active granules ; e. f. smooth, or with longitudinal striie, 

 never granulate. 



The subdi-v^isions of this genus cannot always be rigidly adhered to, as 

 certain species might sometimes seem to agree almost as well with another 

 division as with that in which they are placed. 



* Frond scarcely tapering, the curvature 

 very slight, gradual and equal; lower 

 margin nearly straight or slightly con- 

 cave ; ends truncate or broadly rounded; 

 e.f. with or without longitudinal strice. 



Clostebitim: didymotocum (Corda). — 

 Frond stout, six to ten times longer than 

 broad, nearly straight, very slightly taper- 

 ing to the extremities, upper margin 

 slightly convex, lower nearly straight or 

 very slightly concave, sometimes slightly 



inclined upwards at the end ; ends trun- 

 cate, reddish ; large granules in a single 

 series ; e. f. reddish, especially near the 

 ends, strice faint ', central sutm-e evident, 

 sometimes accompanied by two others 

 dividing the frond into four portions. 

 L. 1-65"; B. 1-813". (iii. 39.) G.B.,I., 

 F., G. a, three transverse sutures; /3, 

 one. = C. subrectum (Kg.), C. Baileyamim 

 (Breb.). 



C. obtusum (Breb.). — Frond minute, 

 fom' to ten times as long as broad, 



