OF THE DESMIDIE^. 



^39 



S. monticidomm (Breb.). — Segments 

 in f. V. broadly elliptic, smooth, wdtb a 

 forked spine on each side, and at the end 

 six stout conical projections directed up- 

 wards, each terminated hij an acute spine ; 

 e. V. ynth three or four acute angles, sides 

 concave, the ter mined, projections extend- 

 ing on each side, confiuent at their bases, 

 from beneath which a mimde, subulate, 

 spine-like projection arises between them 

 and each angle. L. 1-500" ; B. 1-700". 

 r=.Stephanoxanthi^im monticulosum (Kg.). 

 G.B., L, F. 



S. Ehrenbergianum. — The longitudinal 

 outline of the segments obliquely oval, 

 the inner margin convex, diverging, the 

 outer margin very convex and broadly 

 truncate at the ends ; the sides in e. v. 

 slightly undulate, membrane smooth, 

 having at each angle a large spine, di- 

 vided to the middle, consisting of two 

 legs, and on the terminal surface three 

 pairs of such spines, and between each 

 of them and the angles a pair of smaller 

 simpler spines. = Phycastrum Ehrenber- 

 giamwi (^ag.). "L. 1-66'"; thickness 

 1-70'"." We have not seen a dra^ving 

 of the above species, and give the above 

 description following as nearly as pos- 

 sible Nageli's own words, inserting it 

 here as most probably its most fitting 

 place. 



4* Segments with numerous simple acute 

 spines, in f, v. no one in particular ter- 

 minating the opposite lateral extretnities ; 

 e. v. angles etitire, rounded, the spines 

 scattered. 



S. hirsutum (Breb.). — Segments in f.v. 

 semiorhicular, separated by a linear con- 

 striction, covered with very minute, very 

 numerous, close-set hair-like spines ; e. v. 

 with three broadly rounded angles, the 

 spines evenly and numerously scattered ; 

 sides slightly convex. Sporangium or- 

 bicular, beset with short spines, branched 

 at the apex. L. 1-676" to 1-468" ; B. 

 1-833" to 1-Q80" . =X.anthidimn hirsutu?n 

 (Ehr., Kg.), Gonioeystis (Trigonocystis) 

 muricata (Hass.). G.B., I., F., U.S.A. 



S. pilosum (Nag. sp.). — Segments in 

 f. V. obliquely elliptic, slightly divergent, 

 the outer margin more tm-gid than the 

 inner; e. v. with three rounded angles, 

 sides concave ; scattered all over, except a 

 small space at the centre, with extremely 

 fine hair-like spines, mimdely capitcde cd 

 their extremities; smface between the 

 spines smooth. '' L. 1-55"'; thickness 

 1-66'"." Phycastrum pilosum i^i.^.). M. 



de Brebisson is disposed to doubt the 

 accm-acy of Nageli's drawing {Einzell 

 Alg. 8 A. fig. 4), the spines are indeed 

 so very curious. 



S. Brebissonii (nobis). — Segments in 

 f. V. ovato-lanceolate, the lateral extre- 

 mities rounded and famished thereon 

 with numerous short, close-set, hair-like 

 spines, otherwise smooth ; e. v. with three 

 broadly roimded angles, the spines eon- 

 fined to the extremities, sides concave. = 

 S. pilosum (Breb.). F. We are obliged 

 to alter the specific name of this species, 

 — pilosmn having been employed by Na- 

 geli before for the preceding species. 



S. erosum (Breb). — Segments in f. v. 

 elliptic, the lateral extremities furnished 

 with numerous extremely short acute 

 sjjines, sometimes inconspicuous, sur- 

 face granulated all over; e. v. with three 

 broadly rounded angles, the spines con- 

 fined to the angles, sides concave. F. 



S. echinatum (Breb.). — Segments in 

 f. V. elliptic, fm-nished with manerous 

 sjiines, somewhat broad at their base, ex- 

 ceedingly acute, chiefly confined to the outer 

 margin ; e. v. with three angles ; angles 

 and sides broadly rounded, bordered all 

 round by the spines. F. 



S. tcliferum (Ralfs). — Segments in f.v. 

 elliptic or subreniform, furnished with a 

 few scattered, elongate, subulate, acute 

 spines ; e. v. with three broadly rounded 

 angles, the sjnnes scattered, chiefly con- 

 fined to the extremities, surface between 

 the spines smooth, sides concave. Spo- 

 rangium orbicular, beset with numerous 

 elongate linear spines, forked at the apex. 

 L. 1-597"; B. 1-643". (m, 20, e. v. 21.) 

 G.B., I., F. 



S. Hystrix (Ralfs). — Segments in 

 f. V. subquadrate, extremities somewhat 

 rounded, end ynargin nearly straight, fur- 

 nished with a few scattered, subulate, 

 acute spines, chiefly confined to the late- 

 ral extremities ; e. v. with three or four 

 broadly rounded angles, the spines scat- 

 tered, chiefly confined to the extremities, 

 sides concave. L. 1-1075" to 1-1020" ; 

 B. 1-1165" to 1-954". G.B. 



5 * Segments ivith numerous short, trun- 

 cate, emarginate, scattered spines, prin- 

 cipally confined to the margins; e.v. 

 angles rounded; if angles spinous, no 

 sjjine in particidar conspicuously larger 

 than the others terminating the angles. 



S. spongiosum (Breb.). — Segments in 

 f.v. sejniorbicular, furnished with scat- 

 tered short, stoid, forked spines, the 

 spines at the lower basal angle of each 

 3b2 



