Bibliographic Detail
West, W. & West, G.S., 1895
Reference:
West, W. & West, G.S. (1895). New American algae. Journal of Botany, British and Foreign 33: 52 only.
Abstract:
NEW AMERICAN ALGAE.
By W. West, F.L.S., and G. S. West, A.R.C.S.
Pediastrum duplex Meyen. (P. pertusiun. Kiitz.), var. gracil-
LiMUM, n. var. Var. cellulis gracillimis, periphericis arcuatis cum
processibus duobus longis tenuibus emarginatis ad apices; cellulis
reliquis 4-radiatis ; lacunis permagnis. Diam. usque ad 87 fi.
This variety is similar to var. reticulatum Lagerh. (Bid rag till
Banned. Stockholmstr. Ped., Protoc, PalmelL, Ofvers. af K. Vet.-
Akad. Fork., 1882, p. 56, t. ii. f. 1), but the cells are much more
slender, the processes narrower and with emarginate apices, and
the spaces between the cells are very much larger.
Tetraedron tortum, n. sp. T. magnum, irregulariter triangulare,
contortum, lateribus curvatis, convexis, subconvexis, vel
concavis sed in medio leviter convexis; angulis leviter productis,
spina longa valida acuta vel acutissima ad angulum unumquemque
instructa ; membrana crassa glabra. Diam. sine spin. 73-81 /x,
cum spin. 108-117 /x; crass, circ. 42-44 /x.
The large size, peculiar bent and twisted triangular form, furnished
with the strong spines at the angles, distinguish this
species from all others.
Radiofilum apiculatum, n. sp. E. cellulis transverse ellipticovel
rotundo-rhomboideis, angulis lateralibus subapiculatis, cellulis
conjunctis arete in fills longis flexuosis. Contentum chlorophyllosum
cellularum cum pyrenoidibus magnis singulis. Long. cell. 4-4-4 /x;
lat. cell, cum apic. 4*6-5-6 fx.
The smaller somewhat rhomboidal cells with lateral apiculations
distinguish this species from the only other one of the genus, viz.,
R. conjimctivwn Schmidle (Aus der Chloroph.-Fl. der Torfstiche zu
Virnheim, Flora oder allg. Bot. Zeitung, 1894, Heft 1, p. 47,
taf. vii. f. 4, 5). The filaments of R. apiculatum are long and
flexuose, as distinguished from the short fragile filaments of R.
conjiinctivum; moreover, the cells are not so remote as in the latter
species, and are arranged more or less in pairs, the minute apiculi
on the cells of each pair often being directed slightly towards each
other.
The material was not in the living state, but traces of a
gelatinous investment with a radiating structure were observed.
