220 FRESH-WATER ALG^ FROM BURMA.
TMs tiny species is oliaraotevized by the minutely seitato-crenate processes, wliioli are horizontal
in file front view, but are obliquely disposed in tlie vertieal view. Seen from the apes the semicell
is triangular, with three straight processes, one margin o{ each process being a direct continuation
of one of the three sides.
It ifl perhaps nearest to St. Utmmimum "W. & G. S. "West (Alg. Madag. 1895, p. 78, t. 8,
i. 43), but is distinguished by the horizontal position of the processes in the front view, by their
oblique arrangement in the vertical view, and by tlio more minute orenulation of their margins.
150. Stauuastkum bicoronatdm Jolinson. Ra r e Desiu. U. S. 1894, p. 290, t.
211, f. 9.
Forma processibus paullo loogioribus et angustioribus.
Long. 18-19it ; lat. cum proc. 27-32;^ ; lat. isthm. 6-7/i.
ZZai.—Muiisang, near Hsipaw (No. 24193).
151. Stàdrasteum paballelum sp. n.
St. parvum, circitei- 2—3i-p!o latius quam lontjuiii (cum ürocessibus), leviter
constrictum ; aemieellulic subquadrata), angulis basalibus levissinie rotundatis, angulis
superioribus in processus longos rectos horizontaliter dispnsitos productis, marginibus
processuum serrato-dentatis, apicibus processimm tridenticulatis, apice semicelliilaì elevato
et late truncato-retaso ; a vertice visce triaagulares, lateribus leviter coueavis,
angulis in processus longos productis, marginibus processuum denticulatis, cum verruca
magna truncato-emarginata intra marginem lateralem iinumquemque ; annulo granulorum
10 circa basin semiceliularum.
Long. 17//-; lat. sine proc. circiter 7-6;^, cum proc. 32'0-37ìì; lat. isthm.
Jlab.—Mansang, near Hsipaw (No. 24193).
•This Staurastrum is characterized by the elevated apex of the semicells. by the horizoufally
disposed, serrate-dentate procesEes, and by the ring of granules round the base of the semicells. It
does not appear to be very closely related to any other described species.
152. Staurastrum subikdentatum sp. n. (Fl. xv, figs. 21, 22).
St. subparvum, duplo latius quam longum (cum processibus), subprofunde
constrictum; semicellula: quadrato-trapeziformeii, vermca bigranulata ad basin utrobique,
incisura subprofunda et aperta supra verrucam bigranulaiam, angulis su2)erioribus in
processus longos levissime et gracile incurvatos productis, marginibus processuum
minute et acute nodulosis, apicibus processuum tridenticulatis, apice semicellul® leviter
elevato spinie parvis 4-5 piajdito (spinis pa^pe geminatis); a vertice visas biradiatas
corpore late elliptico, polis in processus longos acuta nodulosos jiroductis, spinis mznutis
4-5 (plerumque geminatis) intra marginem lateralem corporis utrobique.
Long. 30-31IT; lat. cum proc. 54-62;^; laf:. isthm. 7-6-8/^; crass. 11m.
Mansang, near Hsipaw (No. 24193).
This species is nearest to St. indentatwn "W. & G. S. West (Freshw. Alg. Ceylon, 1902
186 t. 22, f. 10-12), but is distinguished in the front view by its proportionately greater breadth,'
by its broader and more quadrate semicells, with differently arranged verniete at the sidea, and by
the different choraoter of the apes (which is elevated and furnished with spices). The processes are
also more slender, and their apices are tri denti culate. Io the vertical view the body of the gemiceli is
broadly elliptic (not globose), and the margins of the processes are as rough as in the front view
STAURi STRUM. 221
It should also be compared with Si. lepidum Borge (Trop. u, subtrop. Siissw. Chlor. 1899, p.
SO, t. 2, f. 45), from which it differs in the veirucation of the semicell, and in the nature and
direotion of the processes, In St. lepidum the margina of the processes are denticulate in front view
and smooth in the vertical view, whereas in St. subinrlentatum the pxooesaes are nodulose, eaoh nodulation
being equally developed all round the process On the apices of St. lepidum are four prominent
ieeth forming the corners of an elevated area, and very conspicuous at the sides of the vertical view
but in St. iubimkntatwn there are no corresponding teeth on the elevated apes,
153. Staurastrum compsobrachiatuv sp. n. (PI. xv., figs. 23, 24).
St. subparvum, circiLer 1^-plo latius quam lonerum, modica constrictum ; semicellulae
campanulalie angusta; sed inflata; ad basin, parte superiori marginum lateralum late
divergenti, apice conveso, angulis superion'bua in processus longos et gracile recurvatos
(primum horizontaliter dispositos, turn valde incurvatos apice extrorsum curvato) productis,
marginibus proce?fiuum minute cremilatis, apicibus processuum minute bispinatis,
cum denticulis minutis ad basin processuum (plerumque denticulis 2 inferne et uno
superne); a vertice vis© elliptic®, polis in processus longos productis, tumore magno
truncate ad medium utrobique, marginibus processuum minus crenulatis et apicibus
unispinatis (ut visis); membrana glabra.
Long 35-36/ì; lat. cum proc. 50-57-Óìì; lat. isthm 4'2-5-6ìì; lat. bas. semicell.
7-2-9^; cross. 13^.
i r a i . — I n the Kan-gyi at Mudon (No. 24505).
This pretty little Staurastrum was observed in abundance, and does not appear to be closely
allied to any other species. It is readily distinguished by the graceful curvature of the processes
which are at first horizontal, then strongly incurved with the apices turned outwards. The margins of
each process are minutely crenulate, and the apex is furnished with a pair of small spines asymmetrically
disposed. The small denticulations^ above and below, at the bases of the processes, were
preseut on all the specimens examined. The large truncate protuberances in the middle of the
upper part of semicells are also very characteristic.
154. Staurastrum gracile Ralfs, Brit. Desm. 1848, p. 136, t. 32. f. 12.
Var. VEKEncosuii W. & G. S. West, Alg. Madag. 1895, p. 77, t. 9, f. 1.
Lat. cum. proc. 80 ¡x.
Mansang, near Hsipaw (No. 24193).
15Ò. Staurastrum Sonthalianum Turn. Fresh^. Alg. E. India, 1893, p. 124,
t. 14, f. 27.
Forma ad basin semiceliularum glabra (sine verrucis).
Long. 39^; lat. cum proc. 61-69^; isthm. 12-5/i ( P I . xvi, fig. 6).
//a5.—Mansang, near Hsipaw (No. 24193).
Turner figures the processes in the vertical view with smooth margins, but we do not find this
to be the case.
150. Staurastrum Sebaldi Reinscb, 1867; Algenfl. Frank. 1867, p. 175, t. 11, f. 1.
Forma orientalis.
Forma minor, marginibus inferioribus semiceliularum undulatis.
Long. 45^; lat. cum proc. 53-56^; lat. isthm. 17/u. (PI, xvi, fig. 9).
iiai.—Man sang, near Hsipaw (No. 24193).