218 FliESn-WATKE ALG^ PfiOJI BURMA.
This species closely resembles Si. stdmo»/icu¿ostm Roy & Bias. (Jap. Desm. 1886, p. 238,
t. 26S, f, 7) in the orrangement of its emarginatc warts and in the form of the vertical view.
I t diGers in the trapezoid semioells, the tvidest part of which is at the base, in the etraighter
sides of the narrower siuua, and ia the presence of two pairs of tniaute spines on eaoh lateral
margin of the vertical view. The four warts forming a chain across ths dorsal paxt of the
semicells from angle to angle are bispinate in Si. sitbmoniieuiosmn, but they are only emaiginate
in Si. Iiau'n?i(/ense.
136. STAURASTEUSI BURKILLII sp. n. (PI. xvi, fig. 3).
St. magnum, rotimdato-ellipticum, circiter l¿-plo longius quaui latum, profunde
constrictum, sinu valde aperto (late ovato) apiceni versus late conico ad partem
esteriorem contracto; semicsllulco elliptico-subsemicirculares, ventre convexo, marj^ine
esterioii semicirculari cum undulis depressis 7, angnlis basalibus in niamillos
rotundato-conicos deorsuni productis; a vertice visas triangulares, lateribus leviter
concavis, anguHs latissime rotundalis iu medio cum iucisione profunda et aperta;
membrana dense scrobiculata et ad ángulos subincrassata.
Long. 113/^; la:. 96-99/i; lat. isthm. 36;^.
iTai. Mansang, near Hsipaw (No. 24193).
Tliis hnndsoms S¿a?irí!striim is related to Si. Zahtbrmkneri Liitkem. {Desm. Central China, 1900,
p. 125, t. 6, f, 41-43), but is at once distinguished by its estraordinary sinus, the deeply cleft
angles, the undulate margin of its semicells, and the concave sides of the vartioal view. Lütkemüller's
speoies was described from the Ningpo Mountains in Central China, and a variety of it—
var. mamillaium—has been found in Siam {oide W. & G. S. West, i'resliwa. Chlorophy. Koh Chang,
1901, p. 94, t, 3, f. 35-37). This variety is principally distinguished by the bilobukto or
bimamillate angles, and in a sense it stands intermediate between typical St. Zahlbruckneri and
St. BnrkilHi. In the latter the angles of the semicells are still more deeply cleft, this feature
being particularly evident in the vertical view, in which the broad angles possess a relatively
deep median notch. It is,' bowever, the sinus, at first widely open and then partially closed,
which gives the distinguishing aspect to St. Burkillii.
137. STAURASTEUJI PUNCTULATUM Bréb. in Ralf's Brit. Desm. 1848, p. 130, t.
34, f. 10.
Long. 28-32/x; lat. 23-26/i; lat. isthm. Q/x.
Jiah.—In springs ou the river bank at Bhamo (No. 21501).
138. STAUSASTKUM DILATATOJI Ehrenb. Lifus. 1838, p. 143, t. 10, f. 13; Ralfa
Brit. Desm. 1848, p. 133, t. 21, f. 8.
Var. OBTUSlLOBUii De Not. Desm. Ital. 1867, p. 52, t. 4, f. 47; Nordst.
Preshw. ¿Ig. N. Zeal. 1888, p. 41, t. 4, £. 19.
Long. 34-5^; lat. 35-27^; lat. isthm. 7-5;^.
J7a5.—Momauk, east of Bhamo (No. 21551).
139. STAUBASTRUM KETUSUM Turo. Freshv?. Alg. E. India, 1893, p. 104, t. 13,
f. 13.
Var. PUNCTULATOM Eichl. & Grutw. Noun. Spec. Alg. Nov. 1894, p. 174,
t. 5, f. 44.
Long. 30^; lat. 20^; lat. 7-5^ (PI. iv, fig. 30-32).
iiaJ.—Mansang, near Hsipaw (No. 24191).
STAUEASTBUM. '^'LL
This variety varies very much in the form of the Bcmicella. The Burmese specimens are less
pyramidate, with convex sides, and the apices are broader and less retuse (PI. xv, fig. 30).
We also figure for comparison some examples from Ceylon which show considerable variation in tho
form of the semicell. We have previously mentioned that the "var. punctulatum" probably differs
in no way from Turner's St. rdwum, as all the tropical forms of this species which have sinoa
been found are punctulate, and Turner himself was very doubtful oonceming the point.
140. STAUEASIEUM L/-EVISPINUM Hiss. Desm. Windermere, 1884, p. 195, t. 5, f. 5.
Var. TSOPicuM var. n. (PI. xvi, fig. I).
Cellula3 subduplo latiores quam long® (cum proeessibus), corpore seraicellularum
depresso-globoso, sinu acutangulo levissime acuminato ad apicera, proeessibus leviter
craasioribus; semicellulge a vertlcc vis® 4 radiatai.
Long, sine proc. 20;^; cum proc. 25/^; lat. cum proc. 36-39^; lat. isthm. 9-5/^.
Sab.—Mansang, near Hsipaw (No. 24193).
141. STAURASTEUJI AVICULA Brcb. in Ralfs, Brit. Desm. 1848, t. 23, f. 11.
Var. ROTTINDATUM var. n. (PI. xv, fig. 25).
Cellula; H-plo longiores quam lata3, angulis rotuudatioribus cum spinis distinctis
binis instructis; membrana irregulariter granulata.
Long. 37-5-39i^; lat. sine spin. 31-36/^; cum spin. 38-44;^; lat. isthm. 9-5,..
i7aj_Mansang, near Hsipaw (No. 24193).
The relative proportions and t i e rounded angles of the semicells characterise this variety. It is
graDUlate almost as in vnr. tuharcuatum (Wolle) West.
112. STAUBASTRUM PROTECTUM sp. n. (PL xvi, fig. 12).
St. submediocre, pasne duplo latius quam longum (cum proccssibusi, profunde
constrictum, sinu valde aperto; semicellukt! late subtriangulares, margiiiibus inferioribus
subrectis, a pice leviter con vex o, angulis in processus validos sublongos sursum divergentes
.gubglabros (sparse et delicatissime ponctatos) prodactis, apicibus processuum
spinis longis claobus praiditis; apicibus semicellularuui verrucis parvis bidentioulatis
circiter 4 et verrucis iis similibus 2 infra apicem ornatis; a vertice visie triaugularos,
lateribus subrectis, anguKs in processus validos productis, verrucis parvia bidentioulatis
duobus ad medium mavginis lateralis uniuscujusque et cum annulo verrucarum
6 intra luarginea iis similium.
Long, sine proc. 35/i, cum proc. 46*^; lat. cum proc. 66m; lat. isthm. 8-5/^.
i7ai.—Mansang, near Hsipaw (No. 24193).
This speoies is nearest to St. arcuntum Nordst. (Norges Desm, 1873, p. 36, t. 1, f. 18)
but differs in the longer processes, which are furnished with a terminal pair of much longer and
more slender spines, in the ring of six apical worts (which are small and bidentieulate—not
bifurcate procespes as in St. arcuatum), and in the possession of a pair of small bidentieulate warts
at the middle of each side of the vertical view. There are thus twelve bidentieulate warts on eaoh
semicell, a ring of sis apical ones and three pairs of lateral ones. The processes are smooth in
outline, but exhibit a few scattered punctulations.
WoUe has figured a Staurastrum (Desmids U. S. 1884, t. 46, fig. 13 and 14) under the name of
St arcuattwi which somewhat resembles St. proteotnm, but his figure is not very good. It Wolle's vertical
view is correct, his plant agrees with St. protecium in the possession of a number of lateral bispinulate
warts but in outward from and in other characters the two are very different from eaoh other.
ABN. BOY. BOT. QARU. CALCUTTA VOL. TI.