178 MESSRS, W. WEST AND G. S. WEST ON 
226. STAURASTRUM RETUSUM, W. B. Turn. in K. Sy. Vet.-Akad. Handl. xxv. 1893, no. 5, 
p. 104, t. 13. fig. 13. 
Var. PUNCTULATUM, Eichler & Gutw. in Rozpraw. Wydz. Akad. Umiej. Krakow, 1894, 
p. 174, t. 5. fig. 44. 
Long. 15:5-24 u ; lat. 15:5-23 4; lat. isthm. 3°6-5°5 u. 
-Hab. Paddyfields, Heneratgodha. 
The specimens observed varied very greatly in size. The cell-wall is minutely punctu- 
late all over, the punctulations being more marked at the angles, and in many cases the 
angles are distinctly thickened. It is highly probable that the var. punctulatum is 
identical with the typical form, as Turner's description of Wallich's figure is not definite 
as implied by the expression “ glabrze ?," and probably Wallich's figure is not good. 
227. STAURASTRUM MUTICUM, Bréb. in Menegh. " Synops. Desm.,’ in Linnea, xiv. 1840, 
p. 228; Ralfs, Brit. Desm. 1848, p. 125, t. 21. fig. 4 
Long. 33°54; lat. 294; lat. isthm. 9 u. 
-Hab. With the preceding species. 
298. STAURASTRUM GIGANTEUM, sp. n. (Pl 21. fig. 20.) S. permagnum, ellipsoideum, 
circiter 1i-plo longius quam latum, profundissime constrictum, sinu sublineari et 
paullo aperto; semicellule semielliptieze, angulis basalibus rectangularibus incras- 
satis et submucronatis ; a vertice vise triangulares, lateribus paullo convexis, angulis 
incrassatis; membrana punctulata. 
Long. 1604; lat. 110 u; lat. isthm. 32 p. 
Hab. Paddyfield between Kosgoda and icakatphaehabundad 
This is a very large Desmid, and at first we thought it a unique species of the genus, 
but since we wrote our description we have observed that it somewhat resembles a 
recently described Chinese species—/S. Zahlbruckneri, Lütkem. (in Annalen des K. k. 
naturh. Hofmuseums, Wien, xv. 1900, p. 125, t. 6. figs. 41-43). 8. giganteum is 
easily distinguished from the latter species by its much larger size, its deeper constriction 
and open sinus, and by its vastly different basalangles. The sides of the vertical view 
are also more convex, and the angles are not so rounded. 
229. STAURASTRUM VILLOSUM, sp. n. (Pl.21.fig. 19.) S. parvum, pæne tam longum 
quam latum (sine spinis), profunde constrictum, sinu acutangulo aperto; semi- 
cellula: subellipticze, spinis longissimis delicatissimis subcurvatis numerosis preedite ; 
a vertice vise triangulares, lateribus levissime concavis, angulis acute rotundatis, 
spinis longissimis curvatis angulos versus confertioribus. 
Long. sine spin. 27 », cum spin. 354; lat. sine spin. 25 p, cum spin. 44; long. spin. 
7-5-10 u; lat. isthm. 7 m. 
Hab. Paddyfields, Heneratgodha. 
This plant may be compared som S. sagittiferum, Borg. (in Vidensk. Medd. naturh. 
Foren. Kjóbenhavn, 1890, p. 950, t. 5. fig. 46), but it differs from that species entirely, 
in the larger number, the greater Fie er and different arrangement of the spines. 
The spines are also more numerous at the angles, and differ from those of any other 
