CLOSTERIUM. 



193 



CI. parvum, eellulis diameiro circiter 30-plo longioribus, parte mediana oellohv 

 recta cum margimbus parallel*, apices versus gradatim attenuatis et leviter incurvatis, 

 pohs angustis cum marginibus parallel*, apicibus obtusis ; membrana glabra e 

 achroa; pyrenoidibus in serie unica in semicellula unaqaaquo 5; locellis apicalibu 

 elongat* et corpusculis— ?— includentibus. 



Long. 186m; lat. 5'7/»; lat. apic. 13**. 

 Hab. — Mansang near Hsipaw (No. 24193). 



The Closterium described above is evidently the same as that figured by Racibon-ki iron 



Australia under the name of ■ Ol. macilentum var. substr i<josum : His measurements are:— long. 

 155-215^; lat. 5-6/*; lat. apic. 2/i. The Burmese forms had slightly narrower apices. 

 Eaciborski states that the Australian plant is "forma intermedia inter C. macil'ntm et C. 

 strigosum, eemicellulis sub apiee magis attenuatis quam in C. macilento," but we do not think it 

 is near either of those species. CI. macilentum Breb. is much larger and the attenuation of the 

 cells is very gradual from the middle to the apices, which are by no means very narrow. CI 



strigosum Breb. is a much larger and stouter speoies, with incurved, rapidly attenuated apices, 

 which are rot drawn out into long processes. 



The apices of CI. subsirigosum are drawn out into long, narrow, colourless processes with parallel 

 margins, into which the chloroplasts do not enter. The apical vacuole thus occupies more than 

 one-third the length of the semicell. 



m 



47. Closterium gkacile Brdb., 1839 ; W. & G. S. West, Brit. Desm. i, 1904, 



p. 166, t. 21, f. 8-12. 



Long. 146/*; lat. 4'&>. 

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



48. Closterium acutum (Lyngb.) Br£b. in Ralfs, Brit. Desm. 1848, p. 177, 



t. 30, f. 5; t. 34, f. 5 a, b, d-f; W. & G. S. West, Brit. 

 Desm. i, 1904, p. 177, t. 23, f. 9-14. 



Long. 138-147^; lat. 4*5-6/*. 



fla*.— Momauk, east of Bbamo (No. 21551). Between Thingan-nyi-naung and 



Kawkareik, in the side-channel of a stream (No. 24483) 



t 



49. Closterium Ralfsii Breb., 1845; Ralfs, Brit. Desm. 1848, p. 174, t. 30, 



f. 2 



Var. hybridum Rabenb. Krypt. Fl. Sachs. 1863, p. 174 ; W. & G. S. We 



Brit. Desm. i, 1904, p. 183, t. 24, f. 8-13. 

 CI. lineatum Ehrenb. var. sandviceme Nordst. Alg. aq. dulc. et Char. Sandv 

 1878, p. 9, t. 1, f. 10-12. 

 Long. 430/*; lat. 31/*. 



Hab.— In swamp, Katha (No. 22677) 



50 



Closterium decorum Breb. Liste Desm. 1856, p. 151, t. 2, f. 39; W. & 



G. S. West, Brit. Desm. i, 1904, p. 184, t. 17, f. 7, 8 ; t. 28, f. 1-3. 

 CL crassum Delp. Desm. subalp. 1877, p. 121, t. 18, f. 22-30. 

 CI Delpontei Wolle, 1885; Freshw. Alg. U. S. 1887; p. 25, t. 55, f. 9. 



Forma minor. 



Akn. Roy. Bot. Gabd. Calcutta Vol. VI 



