154 MESSRS. W. WEST AND G. S. WEST ON 
119. EUASTRUM FISSUM, sp. n. (Pl. 20. Des 17, 18.) E parvum, circiter duplo longius 
quam latum, profundissime constrictum, sinu angusto-lineari extremo ampliato ; 
semicellulze semielliptice vel pyramidato-ovate, angulis basalibus subrectangularibus 
(lateribus extrorsum divergentibus), lateribus in medio (circ.) retuso-emarginatis et 
valde incrassatis, supra partem retusam laterum cum dente parvo obtuso, apicibus 
rotundo-truneatis in parte mediana incisura profundissima angusto-lineari, cum 
granulo intra marginem ad medium utrobique, tumore basali parvo emarginato 
supra isthmum ; a latere visæ angusto-ovate, cum tumore emarginato-truncato 
prope basin et granulo supra tumorem utrobique; a vertice visæ elliptica, tumore 
parvo emarginato ad medium utrobique, polis rotundatis. 
Long. 345-41 u; lat. 19-22; lat. isthm. 3-4, ; crass. 1375 n. 
Hab. Paddyfields, Heneratgodha. 
At first sight it may appear to be undesirable to create another specific name for an 
Euastrum of the nature of E elegans, E. pseudelegans, &c., but on further consideration 
we think it solves a difficulty. Numerous specimens were examined and all possessed 
exaetly the same structural features, and rather than refer the plant to a badly described 
form which may be itself merely a variety of some other “ elegans-like” Huastrum, we 
think it much better to give it a name by which it can always be recognized. The plant 
possesses certain characters, such as the very deep polar incision and the emarginate 
thickened notch at the sides, which at once distinguish it from Æ. elegans and its 
varieties, not to mention other peculiarities of less importance. 
Almost the nearest approach we can find to E fissum is a figure given by Turner (in 
K. Sv. Vet.-Akad. Handl. xxv. no. 5, t. 10. fig. 37) of E. subspinosum, W. B. Turn., 
var. tumida, W. B. Turn. ; but E. subspinosum, W. B. Turn., 1893, E annulatum, W. B. 
Turn., 1893, and E éncurvatum, W. B. Turn., 1893, are most certainly referable to the 
same species as E. pseudelegans, W. B. Turn. 1885! And, perhaps, Æ. pseudelegans 
would be more correctly placed as a variety of E elegans with rounded basal angles. 
It may also be compared with E bilobwm, Lütkem. (in Verhandl. d. k. k. zool.-bot. Ges. 
Wien, xlii. 1892, p. 561, t. 9. fig. 13). 
120. EvAsTRUM ROSTRATUM, Ralfs, 1844; Brit. Desm. 1848, p. 88, t. 14. fig. 6. 
Forma cellulis paullo latioribus, lobulis superioribus loborum lateralium emarginatis. 
Long. 474; lat. 354; lat. lob. polar. cum spin. 22-23 4; lat. isthm. Gu (Pl. 20. 
fig. 13.) 
Hab. Paddyfields, Heneratgodha. 
Forma cellulis paullo latioribus, cum granulo magno infra basin incisuræ apicalis 
utrobique (ut in var. wmbonato). 
Long. 47»; lat. 31g; lat. lob. polar. cum spin. 21-22:5 u; lat. isthm. 75; crass. 
20:5 pu. (Pl. 20. fig. 12.) 
Hab. With the preceding form. 
Both these forms are relatively wider than E rostratum, and somewhat intermediate 
between it and the var. wmbonatum, West & G. S. West. Schmidle (in Flora, Ixxxii. 
1896, Heft 3, p. 310) places E. rostratum, var. umbonatum, as a species (Juastrum 
