214 



FRESH-WATliR ALG^E FROM BURMA. 



//a£._ Mansang, near Hsipaw (No. 24193). 



/ 



St. unicome is a very variable species, of which there are five described varieties. Turner states, 

 in his ' description of St. unicorne that the spine at the extremity of each angle may be curved, 

 straight, convergent, or divergent. In the specimens of St. unicorne var. ceylanicum desoribed from 

 Ceylon the terminal spines were curved and slightly convergent. 



130. Staurastrum cuspidatom Br£b. in Menegh. Synops. Desm. 1840, p. 226; 



Ralfs, Brit. Desm. 1848, p. 122, t. 21, f . 1 ; t. 33, f. 10. 

 JIab.— Mansang, near Hsipaw (No. 24193). 



131. Staurastrum Prainii sp. n. (PI. xvi, fig. 10). 



St. magnum, circiter tarn longum quam latum, profunde constrictum, sinu 

 an^usto apicem versus deinde extrorsum valde ampliato; semicellulae transverse sub- 

 elliptica), apice late truncato (interdum levissime retuso), angnlis lateralibus cum 

 ruamilla parva intus excavata spinam brevem ferente ; a vertice visae triangulares, 

 lateribus in medio retusis, angulis late rotundatis apice extremo subiter et leviter 

 producto et spina brevi praedito; membrana glabra. 



Long. 86-88/*; lat. sine spin. 73-90/*, cum spin. 79-100/*; lat. isthm. 26-28/*. 

 Bab. — Mansang, near Hsipaw (No. 24193). 



This species differs from H. majmculum Wolle and St. magnum Wolle in being proportionately 

 wider, in the flattened apices and more inflated angles of the semi-cell?, in the much narrower 

 apical part of the sinus, and in the short spines which arise from a small hollow projection at each 

 angle. The inflated angles are most clearly seen in the vertical view. 



It should also be compared with St. conspicuum W. & G. S. West, from which it is distinguished 

 by its relatively longer cells "with more inflated lateral angles, each of which is furnished with a 

 short spine situated on the extremity of a hollow mamillate projection. The cell-wall is also smooth. 



132. Staurastrum bifidum Br<Sb. in Ralfs, Brit. Desm. 1848, p. 215 ; Lund. 



Desm. Suec. 1871, p. 62, t. 4, f. 2. 



Long. 31*5/*; lat. sine spin. 29-31/*, cum spin. 48-5 6/* ; lat. isthm. ' 11*5/* 



(PI. xvi, fig. 



Bab. — Mansang, near Hsipaw (No. 24193). 



133. Staurastrum subtrifurcatum W. & G. S. West, Some N. Amer. Desm 



1896, p. 258, t. 16, f. 24. 



Var. majus nob. 



St. subtrifurcatum Schmidle, Ost-Afrika Desm. 1893, p. 56, t. 3, f. 17. 





St. subtrifurcatum forma major W. & G. S. West, notes Alg. u, 1900, 

 p. 295. 



Var. major, semicellulae a fronte visae sinu apertiori, apice leviter retuso; 

 • • a vertice visae angulis subinflatis et acute . rotundatis, lateribus subrectis 



(sed leviter retusis in medio). 



Long, sine spin. 56/*, cum spin. 84-86*5,,; lat. sine spin., 54-55-5/,, cum spin. 

 05-108/*: lat. isthm. 15/*. (PI. xvi, fig. 15). 



Hah.— Mansang, near Hsipaw (No. 24193). * , . ■ 



