OF TKE DESMIDIE.^. 



749 



C. striolatwn (Ehr.). — Frond from six 

 to ten times as long as broad, Innately 

 cm-ved, attennated; upper margin con- 

 vex, sliyhtly dipressed at the centre, lower 

 concave; ends vety obtuse, rounded; 

 large gTanules, in a single series ; e. f. 

 reddish, especially near the ends, strice 

 very numerous, crowded, transverse su- 

 tures nsualli/ three. Sporangium orbi- 

 cular, smooth, placed between the de- 

 hiscing deciduous emptv fronds. L. 1-80" 

 to 1-68" ; B. 1-625" to 1-535". (ii. 2 & 6.) 

 = a ref/ulare (Breb.) ?. G.B., I., F., G., 

 Italy, U.S.A. 



C. intermedium (Ralfs). — Frond slen- 

 der, twelve to fifteen times as long as 

 broad, slightly curved, very gently taper- 

 ing', upper margin convex, gradually 

 arched, lower slightly concave ; ends ob- 

 tuse, rounded ; large gi-anules, in a single 

 series; e. f. pale straw -colom-ed, strife 

 distinct, numerous, hut not crowded; trans- 

 verse sutures usuallv more than three. 

 L. l-77"-l-54" ; B. 1-1073". G.B., I., F. 



C. angustatum (Kg.). — Frond slender, 

 ten to twenty times as long as broad, 

 sublinear, slightly curv-ed, scarcely atte- 

 nuated; upper margin convex, gradually 

 arched, lower concave ; ends truncate, 

 slightly rounded ; large granules, in a 

 single series ; e. f, pale reddish, especially 

 near the ends, strice few (about four), very 

 distinct, transverse sutures usucdly three. 

 L. 1-60" ; B. 1-1142". G.B., I., F., G. 



C.Ju?widum (Ralfs). — Frond very slen- 

 der, from about fifteen to even thirty- 

 five times as long as broad, linear, 

 straight except towards the extremities, 

 which are somewhat curved downwards, 

 ends obtuse ; e. f. nearly colourless, strice 

 not 72umerous, faint, transverse sutures 

 usually three. Sporangium orbicular, 

 smooth, placed between the dehiscing 

 deciduous empty fronds. G.B., I., F. 

 /3, frond stouter, less elongated. 



C. uncinatum (Kg.). — Frond slender, 

 tapering to a stibacute point, suddenly 

 curved dotcnwccrds ; e. f., the body with 

 strice fine and close, absent at the extre- 

 mities. 



C. lineatum (Ehr.). — Frond slender, 

 elongate, from about eighteen or twenty 

 to twenty-five times as long as broad, 

 gently cmwed, very gradually attenuated; 

 upper margin unequally convex, being 

 most curved near the ends, lower concave 

 or somewhat protuberant at the centre ; 

 sides somewhat parallel for a portion of 

 their length ; the extremities gradmdly ta- 

 pering, slender, curved doivnwards, etids 

 obtuse ; large gi-anules, in a single series ; 

 e. f. reddish, strics numerous, clisti?ict, one 



or more transverse lines at the coitrcd su- 

 I ture. Sporangia double, rounded, smooth, 

 in close approximation, their opposed sur- 

 faces fiattened, placed between the de- 

 hiscing, shortly-deciduous empty fronds, 

 and each formed by the mutual conjuga- 

 tion of the contents of the adjacent op- 

 posite segments, L. 1-48"; B. 1-909". 

 (ni. 41, 42.) G.B., I., F., G., Mexico. 

 /3, stria3 spiral ; y, stricie very faint, except 

 at the centre of the fi^ond (Breb.). 



C. decorum (Breb.). — Frond about 

 twelve to twenty times as long as broad, 

 tapering from the centre, graducdly curved ', 

 upper margin equally convex, lower 

 margin concave; extremities attenuated, 

 slender, obtuse ; large granules, in a single 

 series ; e. f. colourless, striae numerous. F. 



5 * Frond gradually curved, tapering, sud- 



denly contracted at the end into a coni- 

 ccd point. 



C. attenuatum (Ehr.). — Frond eight to 

 twelve times as long as broad, gently 

 cm'\ed, gradually attenuated; upper mar- 

 gin slightly convex, lower concave ; ex- 

 tremities suddenly contracted into an obtuse 

 coniccd point; large granides, in a single 

 series ; e. f. reddish, with numerous close 

 striae, central sutm-e evident. L. 1-57" : 

 B. 1-669". (ill. 4:3.) G.B., I., F., G. 



6 * Frond ventricose or narrow-lanceolate, 



rapidly tapering into a distinct beak. 

 (S/jorangia c)i/cifor?n.) 



C. Ralfsii (Breb.). — Frond stout, six 

 to nine times as long as broad ; the upper 

 margin slightly convex, the lower concave, 

 hut ventricose at the middle; each extremity 

 tapering into a narrow, slender, reddish 

 beak, shorter than the body, slightly curved 

 downwards, ends obtuse ; large gi'anules, 

 conspicuous, ia a single series ; e. f. red- 

 dish, especially near the ends, striae nu- 

 merous, close, and distinct, centred suture 

 accompanied by several transverse lines. 

 L. 1-79" ; B. 1-526". G.B., F. 



C. rostratum (Ehr.). — Frond from 

 about ten to fifteen times as long as 

 broad, lanceolate; upper andloicer margins 

 nearly equcdly convex ; each extremity 

 tapering into a narrow, setaceous, nearly 

 colourless beak, nearly equal in length to 

 the body, cm'^-ed do\\Tiwards, ends obtuse ; 

 large granides, in a single series ; e. f. 

 colourless or somewhat straw-coloured, 

 striae numerous, close; suture solitary. 

 Sporangium somewhat crucifonn, its 

 sides concave, its extensions trimcate, 

 attached to the emptv conjugated fronds. 

 (III. 44.) L. 1-69" ; "'B. 1-680'. C. cau- 



