634 MR* W. JOSHUA ON BURMESE DESMIBIEJ!. 



Burmese Desmidieae, with Descriptions of new Species occurring 

 in the neighbourhood of Eangoon. By W. Joshua, F.L.S. 



[Bead 5th February, 1885.] 



(Plates XXII.-XXV.) 



During the winter of 1883-84 I received, through the kindness 

 of Dr. Eobert Eomanis, E.L.S., of Eangoon, some collections of 

 freshwater Algae, taken from the leaves of Pistia Stratiotes. On 

 preparing these for microscopic use, and on frequent subsequent 

 examinations, they appeared to contain so many Desmidiese 

 entirely new to science that I thought a detailed enumeration 

 would be necessary. 



The best collection was made after the rainy season from a 

 pond, or old tank, in the vicinity of Eangoon, situated on the 

 glacis of the fort surrounding the Pagoda, to the right of the 

 south approach. This tank is only of small dimensions, being not 

 more than 30 ft. square and about 20 deep. It appears to be of 

 considerable antiquity, having been placed there in Burmese 

 times, and is said never to be disturbed by cleaning out, a 

 condition conducive to the multiplication of these interesting 

 forms. The surrounding soil is a friable sandstone in beds of 

 shale, producing alum. The locality lies at the eastern estuary 

 of the Irrawady, about 26 miles from the sea, and on elevated 

 ground. 



It may be observed that many of the species are considerably 

 smaller than their northern prototypes ; still some of the Cos- 

 inarieae and Docidieae are of extraordinary size and beauty. 



I am not aware that any special list of Burman Desmids has 

 hitherto been recorded, save a few odd species mentioned by 

 Dr. Gr. Zeller, in Journ. Asiat. Soc. of Bengal, vol. xlii. (p*- xx ' 

 Nat. Hist, i., iv. 1873), the Desmid portion of the Algae collected 

 in Arracan and British Burma by Mr. S. Kurz (I. c.) being there 

 stated to be in the hands of Mr. W. Archer of Dublin. The 

 only lengthened account of Eastern Desmids that I am acquainted 

 with, is that by Dr. G. C. Wallich* from a district of Lower 

 Bengal, situated about 120 miles north-west of Calcutta, 1855; 

 and a few notes of species collected by Herr Grrunow, of Berndorf., 

 Vienna, from the island of Banka, Singapore, 1855. 



* Ann. & Mag. Nat. Hist. (3) v. pp. 184 and 273, pis. 7, 8, 13, and 14- 



