(00 ——— 
THE FRESHWATER ALGJE OF CEYLON, 169 
Long. 26:5 u; lat. 19 u; lat. isthm. 6 p. 
Hab. Rocks in Mahawelli Ganga. 
Perhaps this plant should be renamed, as there is a Cosmarium incisum, Racib., 1885. 
186. CoSMARIUM MEDIOSCROBICULATUM, $p. n. (Pl. 21. fig. 1.) C. parvum, circiter tam 
longum quam latum, modice constrictum, sinu breviter lineari extremo ampliato et 
extrorsum valde ampliato ; semicellulze elliptico-subreniformes, apicibus late trun- 
catis; membrana delicatissime granulata sed marginibus sinus et parte prope 
isthmum glabra, in centro scrobieulis 10-12 irregulariter dispositis; a vertice visse 
compresso-elliptieze, lateribus subparallelis scrobiculatis ad medium, polis subro- 
tundatis minute granulatis ; pyrenoidibus binis. 
Long. 34:5-36:5 p; lat. 33-345 w; lat. isthm. 15 w; crass. 18 y. 
Hab. Paddyfields, Heneratgodha. 
Fron: C. trachydermum, West A G. S. West, and C. punctulatum, Bréb., this species is 
distinguished by the outward form of the cell and the peculiar open sinus. It is also more 
minutely granulate, and possesses a number of well-marked scattered scrobiculations 
forming an irregular band across the centre of the semicells. The vertical view is also 
more compressed, and the poles not so rounded. 
It also resembles to a certain extent C. Raciborskii, Lagerh., but the semicells are 
more broadly elliptical, the lateral angles are much more rounded, and the sinus is 
closed and then ampliated. The serobieulations in the centre of the semicells are 
not present in C. Raciborskii. 
187. COSMARIUM BIRETUM, Bréb. in Ralfs, Brit. Desm. 1848, p. 102, t. 16. fig. 5; G. S. 
West, in Journ. Linn. Soc., Bot. xxvii. 1899, p. 389, t. 10. figs. 22-28. 
Long. 56 u; lat. 45 u; lat. isthm. 15 m. 
-Hab. With the preceding species. 
188. CosMARIUM MARGARITATUM, Roy et Biss. in Journ. Bot. xxxiv. 1886, p. 194. 
Long. 62 u; lat. 48 u; lat. isthm. 16 a. 
Hab. Yn artificial tank, Peradeniya. 
189. CosMARIUM SUBDECORATUM, West & G. S. West, in Journ. Linn. Soc., Bot. xxxiii. 
1897, p. 165, t. 8. fig. 13. 
Long. 57-63 p; lat. 48-50 »; lat. isthm. 15 p. 
Hab. Paddyfields, Heneratgodha. ^ Paddyfield between Kosgoda and Urahaighas- 
mahendai. 
190. CosMARIUM DECORATUM, West & G. S. West, in Trans. Linn. Soc., Bot. ser. 2, v. 
1895, p. 61, t. 7. fig. 21. 
Var. DENTIFERUM, var. n. (Pl 21. fig. 3.) Var. constrictione paullo profundiori, cum 
serie transversa verrucarum oblongarum 4 supra et juxta isthmum; cellulis a 
vertice visis ellipticis. 
