— 170 — 



Var. surculifera Lagerh. in Bih. till K. Sv. Vet.-Akad. Handl. Bd. 13, 

 no. 9, 1888, p. 5, t. I, f. 1. 



Long. 98«; lat. 100/;; lat. isthm. 18//; crass. 49. 



In muddy ricefield. 

 Area: India and Ceylon. 



54. M. tföbii West & G. S. West in Journ. Linn. Soc. bot. XXXIII, 

 1897, p. 162. Euastrum verrucosum Ehrenb. var. Mobil Borge in Bih. 

 till K. Sv. Vet.-Akad. Handl. XXII, no. 9, 1896, p. 13, t. II, f. 18, 19. 

 E. verrucosum forma Möbius in Abhandl. d. Sencknb. naturf. Ges. Frank- 

 furt a. M. 1894, Bd. 18, p. 340, t. II, f. 21. 



M. mediocris, circiter lVö-plo longior quam lata, profunde con- 

 stricta, sinu leviter aperto ad extrem um lineari et subampliato 

 (nonnunquam sinu angusto-lineari extremo ampliato et aperto 

 extrorsum); semicellulæ trilobæ, incisuris latis et rotundatis; lobo 

 polari multo majori, incudiformi, late expanso cum collo latissimo, 

 apice convexo sed in medio late et leviter retuso, extremitatibus 

 lateralibus emarginato-truncatis ; lobis lateralibus breviter subtrapezi- 

 formibus, leviter bilobulatis, lobulo superiori minori cum apice un- 

 dulato-truncatis, lobulo inferiori majori cum margine levissime et 

 subirregulariter undulato; in centro semicellularum tumore magno 

 dense scrobiculato , tumore minimo intra lobum lateralem unum- 

 quemque; membrana cellularum irregulariter et minute granulata; 

 a vertice visæ oblongo-ellipticæ tumore magno utrobique, polis 

 rotundatis, lobo polari oblongo-subrectangulari, lateribus convexis, 

 polo unoquoque in processus crassos breves divaricates duos pro- 

 dueto, lobulo superiori lobi lateralis uniuscuj usque in processus 

 breves divaricatos duos furcato ; a latere visæ truncato-ovatæ, late- 

 ribus in parte superiori concavis. 



Long. Ill — 117 lat. 90—36«; lat. lob. polar. 76—80/;; lat. 

 isthm. 28—31,«; crass. 59—60/;. (Tab. nostr. Ill, fig. 21.) 



We have previously shown this plant to be a Micrasterias and not 

 a species of Euastrum (cfr. Journ. Lin. Soc. 1897, p. 162), but we give 

 here for the first time a complete description of the typical plant. It 

 stands nearest to Micrasterias Americana Ralfs. 



In stagnant water in the jungle, abundant amongst Micrasterias Mahabu- 

 leshwarensis and various Palmellaceœ. 



Area: Australia (Northern Queensland) Also var. Ridleyi from Singapore. 



Var. tetrachastriformis West & G. S. West, n. var. (Tab. nostr. Ill, 

 fig. 22). 



Var. lobis lateralibus reductis, lobulo inferiori attenuato et sub- 

 emarginato, lobulo superiori parvo et acute conico; extremitatibus 

 lobi polaris plus attenuatis. 



Long. 108—120/;; lat. 88-111 f r, lat. lob. polar. 82—96 /;; 

 lat. isthm. 24—31/;. 



This variety, which occurred in a muddy ricetield, is easily distin- 



