198 FRESH-WATER ALQIE FEOM BURMA.
67. EUASTBUJI COKALLOIDES Josh. Burmese Dei 1S86, p. m9 , t. 23, f. 10.
Vav. 8UBINTEGRUM var. D. (PI. XIV, fig. 8).
Var. minus, lobo polari paullo angustiori integro ad margines laterales, ineisura
apicali perangusta et nÙQus profunda, angulis superioribus lobi polaris
unidenticulatis, tumoribus basalibus tribus.
Long. lat. 21;x ; lat. lob. polar, lo/i; lat. istbni. 5-5^; crass. 13^.
Hah.—Mansaug, near Hsipaw (No. 24193).
This variety ^rees with var. trigiLbertm Lagerh. (Desm. aus Bengal; 1888, p. 6) in the
posBOBsion of thie? basal protuberauces on eaoh semioell. It resembles E, pksiocornlloidei W. & G.
S. West, in the nature and disposition of its protiiheranees, hut the apex of the -polar lobo is
troncate, the incisions below the polar lobe are small opea notches, and the lateral lobes are more
projeoting and quadrate.
"We are inclined to believe that the var. tñgiblerum Lagerh. may possibly be the same plant as
Joshua had in view when ho origioally described hia E. cornlloides. He describes and figures only
two basal tumours, whereas all tlie Euoitra of this nature have one central one and generally two
lateral ones, and as we have found bis figures and descriptions to be inaccurate with regard to the disposition
of the tumours on other species, we think this may also be the case in E. coraUoides. This
view is fui-ther supported by the fact that Borge (Trop. u. subtrop. Siissw.-Chlor. 1809, p. 2(5, t. 3,
f . 31), figures three basal tumours on specimens of E. eoralioides which he examined from Singapore.
68. EUASTEOJI PULCFIEERIMUM W. & G. S. West, Freshw. Alg. Ceylon, 1902,
p. 153, t. 20, f. 11.
Var. Divisuir var. n. (PL xiv, fig. 7).
Var. paullo minus, lobis lafceralibus leviter bilobuiatis, lobulis inferioribus retusocnmfginatis,
dentículos marginales carentibus, tumore centrali semicellularum
granulis 4 prfedito.
Long. 44/4; lat. lat. istbm. ; crass. 17-5/^.
JM.—Mansang, near Hsipaw (No. 24193).
This variety differs principally in its bilobulate lateral lobes and in the absence of tho small
teeth íúong the lateral margins. The central tumour is furnished with four larga granules, and the
tumours within the lateral and polar lobes arc also quadrigranulate.
69. EUASTRUM DUBITO Nag. Gatt. einz. Alg. 1849, p. 122, t. 7D, f. 2.
E. loMatum Bréb. Liste Desm. 1856, p. 124, t. 1, f. 4.
E. erosum Lund. var. notaUk West, Alg. Eng. Lake District, 1892, p. 723,
t. 9, f. 17.
Var. TRITUM var. n. (PI. xiv, fig. 6).
Var. paullo minus, lobis lateralibus minus prominentibas, angulis lobi polaris
rotundatis, incisui-a apicali variabili ; membrana glabra.
Long. 22-26,^; lat. 13-14-5^; lat. apic, circiter 8-9^^; lat. isthm. 3-8-4'4;x ;
crass,
Eab.—lu the Kan-gyi at Mudon (No. 24505).
The var. trihim differs from all forms of E. duUum in being less prominently lobed, and in its
rounded polar lobe. The cell-wall is also destitute of markinga. The apical notch varied in depth
and width in the different specimers observed.
ETJASTRIDIUM. 199
E. eromm Lund. var. aUcntuat»m Turn. (Freshw. Alg. of E. India, 1893, t. 10, f. 18, 21)
stands somewhat near to E. ditbium var. trikm, but the apex is rotuse and not incised. Moreover,
the Burmese plants have not the characteristic vertical and side views of E. ei-osum.
7 0 . EUASTBUM BHAMENSE s p . n . ( P I . x i v , fig. 5).
E. minutum, circiter l^-plo longius quara latum, profunde constrictum, sinu
angusto-lineari; semicellula} truncato-pyramidatic, lateribua subirregularitor 3-4-undulatis
et levissimc convesis, angulis basalibus leviter rotundatis vel subrectangulalibus,
angulis apioalibus subreetangularibus vel subobtusis, apice truncato-convexo
et leviter 4-undulato, cum incieura mediana parva et subaperta; a vertice vis®
ellipticie; a latere viste elliptico-ovatíe ; membrana glabra.
Long. 22-23-5^; lat. 15-15-5-5/x; lat. apic. IO'OA'; lat. isthm. 4'8-5'7ÍÍ; crass. 9/I.
Ual.—In springs near the Irrawaddy, Bbamo (No. 21501).
This small species differs from E. hinah (Turp.) Ehrenb. in its more pyramidate cells with
undulate lateral margins and undulate apices. It has also a more prominent apical notch, and tho
semicells are destitute of a oentrnl protuberance. It is nearest to E. UnaU var. suUohatum "W. &
G. S. West, but differs in its undulate apes, its deeper apical notch, and in the absence of the
protuberance from the centre of the semicells.
It should also be compared with E. doliforme W. & G. S. West (Some Desm. U. S. 1898,
p. 289, t. 16, f. 12), from which it is distinguished by its smaller size, its undulate apex and
more rounded apical angles, as well as by the absence of the protuberance at the base of the
semicells.
71. EUASTRUM B:NALE (Turp.) Ehrenb.; W. & G. S. West, Brit. Desm. ii, 1905,
p. 51, t. 38, f. 28, 29.
Jlal.—In springs on the river bank, Bbamo (No. 21501). Between Thingannyi
naung and Kawkareik, in the side-channel of a stream (No. 24483).
72. EUARTRUM DENTICULATDJI (Kirchn.) Gay, Note Conj. du midi de Fratice,
1884, p. 33D; W. & G. S. West, Brit. Desm. ii, 1905, p. 55, t. 39,
f. 1-4.
Í7a5. —Li the Kan-gyi at Mudon (No. 24505). Between Tbingan-nyi-nauiig and
Kawkareik, in the side-channel o£ a stream (No. 24483).
73. EOASTSUM VALIDDM W. & G. S. West, Some N. Amer. Desm. 1896, p.
245, t. 14, f. 32, 33.
Forma angulis inferioribus Bubrectaugularibus, granulis intra ángulos inferiores nullis.
Long. 26/x; lat. 19^; lat. isthm. 4-8/:t; crass, ll^t (PI. xiv, fig. 4).
liaS.—Mansang, near Hsipaw (No. 24193).
This form resembles very much Oomarium midsr/rseceme Eichl. & Gutw. (Nonn. spec. alg. no v.
1894, p. 165, t, 4, f. 9), but differs in the form of the apex and in^the absence of the mediau
I the vertical view.
Euastridium gen. nov.
Cellul® iis Euasiri subsimiles sed non-conipressm, sinu latissime aperto, sine
ineisura apicali ; semicellulaj a fronte visje subtribbaB, apice retuso ; a latere vis«
ixi a fronte visa;; a vertice vtsce ac(inomorphic(e, 8-lobatie.
AKH. EOY. BOT. GARD. CALCUTTA VOL. V I.