THE FRESHWATER ALGZ OF CEYLON. 153 
the lobes and the absence of the large scrobiculation at once distinguish it, however, from 
Euastrum truncatum. 
Quite recently, Schmidle (in Engler’s Bot. Jahrbüch. xxvi. Heft 1, 1898, p. 46, 
t. 2. fig. 37) has described E trifolium, var. concavum ; but, as this variety possesses a 
retuse polar lobe and also a central scrobiculation, it seems to us nearer to E. truncatum, 
Josh. 
Also, the “Micrasterias sp.” mentioned and figured by Borge (in Bih. K. Sv. Vet.-Akad. 
Handl. xxii. Afd. 3, no. 9, p. 11, t. 4. fig. 62) is most probably a close relative, if not 
a variety, of E truncatum, but lack of detail prevents us from arriving at a definite 
conclusion. 
116. EUASTRUM ABRUPTUM, Nordst. in Vidensk. Medd. naturh. Foren. Kjóbenhavn, 1869, 
nos. 14-15, p. 217, t. 2. fig. 3. 
Hab. Paddyfields, Heneratgodha. Paddyfield between Kosgoda and Urahaighas- 
mahendai. 
117. EUASTRUM PULCHERRIMUM, sp. n. (Pl. 20. fig. 11.) Z.submediocre, circiter 14-plo 
longius quam latum, profundissime constrictum, sinu angusto-lineari extremo 
ampliato; semicellulz truncato-pyramidate, trilobze, incisuris lateralibus apertis 
et rotundatis; lobis lateralibus semiellipticis, spinis brevibus (vel denticulatis) 
validis ad marginem et spina singula intra marginem superiorem, in centro juxta 
sinum verruca emarginata magna ornatis; lobo polari maximo transverse oblongo- 
rectangulari, angulis inferioribus mamillatis et bidenticulatis, lateribus subconcavis 
verruca emarginata intra marginem, angulis superioribus dente majore instructis, 
apicibus truncatis et levissime convexis incisura mediana profundissime et subaperta, 
verruca emarginata magna utrobique juxta incisuram medianam; in centro semi- 
cellularum tumore magno annulo granulorum 7 fimbriato; a vertice vise oblongo- 
elliptice, tumore trigranulato utrobique, polis emarginatis verruca emarginata 
utrobique; a latere visæ subovatz, ad basin tumore trigranulato et apicem versus 
verruca emarginata utrobique. 
Long. 59; lat. 364; lat. lob. polar. 29 4; lat. isthm. 7:54; crass. 24 a. 
Hab. Paddyfields, Heneratgodha. Paddyfield between Kosgoda and Urahaighas- 
mahendai. 
Perhaps the nearest species to this is E flammeum, Joshua, but it differs entirely in 
the form of its polar lobe, in its ornamentation, and in its vertical and lateral views. 
Compare also with E evolutum, var. integrius, West & G. S. West. 
118. EvasTRUM PERSONATUM, West & G. S. West, in Trans. Linn. Soc., Bot. ser. 2, v. 
1895, p. 52, t. 6. fig. 19. 
Long. 414; lat. 304; lat. lob. polar. 21 u; lat. isthm. 6 4; crass. 18 a. 
Hab. In artificial tank, Peradeniya. 
