744 



SYSTEMATIC HISTORY OF THE rNTUSORIA. 



the ends somewhat protuberant, smooth, 

 terminating at each side in a imir of 

 short stout processes ])lace(l side hy side 

 (one only of which, however, is apparent), 

 directed upwards and divergent, forked 



at the apex 



with three or four 



angles, each terminated hy the pair of 

 short processes sejjarated by a rounded 

 sinus, sides deeplv concave. L. 1-1220" ; 

 B. 1-2127". G.B., F. 



11 * Segments in f v. tvith each opposite 

 lateral extremity terminating in a colour- 

 less i^rocess, either short, rounded, and 

 dentate, or elongate and entire at the 

 end; e.v. circidar, margined tvith from 

 Jive to seven processes, or compressed, 

 and with hut two processes. (S. poly- 

 morphum sometimes has Jive rays, and 

 the e. V. appears almost circular, hut the 

 extremities of the processes are not entire 

 hut tipped with minute spities.^ 



t End -vdew circular. 



S. sexcostatum (Breb.). — Segments in 

 f. V. suhorhicular, furnished on each side 

 with a short, broad, truncate, dentate pro- 

 cess, and ^dth slight crenate elevations 

 on the outer margin ; e. v. circidar, bor- 

 dered by Jive or six short, rounded, den- 

 tate, colourless marginal rays. L. 1-661" ; 

 B. 1-833" to 1-694". = Goniocijstis {Pen- 

 tasterias) Jenneri (Hass.), Stephanoxan- 

 thium sexcostatujn (Kg.). G.B., 1., F. 



S. margaritaceum (Menegh). — Seg- 

 ments in f. V. gradually widening up- 

 wards, rough with pearly gi'anules, outer 

 margin convex, produced at each side 

 into a colourless, more or less attenuate 

 short /jrooess, having the granules in 

 transverse lineS; blunt and entire at the 



apex ; e. v. circular, bordered by from 

 five to seven short, narrow, obtuse, co- 

 lourless, gi'anulate marginal raj's. L. 

 1-1176" ; B. J-1000" inch _ processes. 

 (hi. 84, e.v. 35.) = Pentasterias marga- 

 ritacea (Ehr. ),Phycastru}7i margaritaceum 

 (Kg.), Goniocystis {Pent.) margaritacea 

 (Hass.), Phycastrum rotundatum (Kg.). 

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

 j S. Arachne (Ealfs). — Segments in f. v. 

 suhorbicidar, rough with minute gi-a- 

 I miles, lower margin tm-gid, outer convex, 

 I tapeiing at each side into an elongate, 

 I slender, incurved process ha\'ing the gra- 

 I miles thereon in transverse lines, entire 

 at the apex ; e. v. circular, bordered by 

 five sle?ider, linear, colourless marginal 

 rays. L. 1-1020"; B. 1-652" incl. pro- 

 cesses. = Goniocystis (Pe)dasterias) arach- 

 • nis (Hass.), Phycastrum Arachne (Kg.), 

 ' P. radiatmn (Kg.) ?. G.B., F. 



2 1 End view compressed. 



S. tetracermn (Ralfs). — Segments in 

 f. V. gi'adually widening upwards, rough 

 with minute gi'anules, outer margin 

 truncate or concave, tapering at each 

 lateral extremity into an elongated, very 

 slender, colourless process, ha-vdng the 

 granules thereon in transverse lines, 

 entire at the apex and divergent ; e. v. 

 much com^jressed, with a process at each 

 extremity. L. 1-2703"; B. 1-1785". = 

 S. paradoxum (Ehr.), Goniocystis (S. ?) 

 paradoxum (Hass.), Phi/castrum parU' 

 doxum (Kg.). G.B., I., F., G., U.S.A. 



[S. enorme (Ralfs) is omitted, this 

 plant having been, as we think, sho^vu 

 by De Bary {op. cit.) to be a Poly- 

 edrium.] 



2. Fronds distinctly, faintly, or not at all constricted at the middle, very 

 rarely less than three times, mostly many times longer than broad. 

 Si)orangia smooth, and either spherical, elliptic, quadi^ate, or cruciform. 



Genus TRIPLOCERAS (Bailey). — Frond very elongate, straight, constricted 

 at the middle ; segments with numerous whorls of knot-like projections, ends 

 three-lohecl, lobes hidentate. Endochrome with a terminal rounded clear space, 

 in which are active granules. 



Triploceras verticillatum (Bailey). 

 — Frond stout, sutm^e prominent, seg- 

 ments about eight or ten times longer 

 than broad, with numerous whorls of 

 prominent, broad, truncate, emarginate 

 projections, (in. 37.) = Docidium verti- 

 cillatum (Ralfs). U.S.A. 



T. gracile (Bailey). — Frond rather 

 slender, sutiue prominent, segments ten 

 or twelve times longer than loroad, with 

 nimierous whorls of prominent, some- 

 what triangular, roundly blunt projec- 

 tions. = Docidium verticillatum (Ralfs). 

 U.S.A. 



Genus DOCIDIUM (Breb.). — Frond very elongate, straight, constricted at 

 the middle ; segments with an inflation at the base (veiy rarely not so), often 



