COSMAEIUM. 



207 



Long. 46-49-5^; lat. 34'5-37u; lat. isthm. 11-5 



1 



Mab 



In swamp 



Katha 



¥\ 



In the Kan-gyi 

 in the side-chan 



Mudon (No. 

 of a stream 



22677) 



Mansan 



24505) 



•as.«. 27^. 

 near Ilsipa 



(K 







4193) 



Between Thingan-nyi-naung and Kawkareik 



24483) 



C. binum appears to be a fairly common tropical species, and exhibits considerable raria 

 tion in the number of lateral and apical crenations. The central tumour also varies in ««». tin 

 number of vertical series of granules ranging from five to seven. The basal series of granule 



below the central tumour 



consisted of a single row in all the 



specimens examined. 



The form of this species described by Raciborski (Desm. Nowe. 1889, p. 93, t. 0, f. 25) from Polan I 

 also has a reduced number of crenations and only one basal row of granules across the semiieelU. 

 Specimens of C. binum from Burma and Ceylon resemble ltaoiborskfs form more than the original 



Brazilian examples. An almost exactly similar form has been described 



Borge from UueentUi 



as C. binum var. australienm (cfr. Borge, Austral. Siisswasserchlor, 1896, p. 2 1, t 3, f. J 2). 



107. Cosmarium subcrenatum Hantzsch in Rabenli. 



Al,r. 



l«S(il, No. 1213, 



9 Rabenh. Flor. Europ. Alg. iii, 1868, p. 164; Nordst. Deem. Ardor. 



1875, p. 21, t. 6, f. 10, 11. 



Forma paullo major; cellule a vertice visa? polis rotundatis. 



Long. 41/a; lat. 29'5-31-5/i. ; lat. isthm. 13/i ; crass. 20/i (PI. xii, fig. 18). 



Hah. 



In springs on the river-bank, Bhamo (X 



21501) 



108 



Cosmarium dichondrum W. & G. S. "West, Alg. Madag. 189 *>, p. 65, t. 

 f. 12. 



Var. subhexagonum var. n. (PI. xii, 



fig. 16). 



Var. semicellulis late truncato-pyramidatis, angulis inferioribus rotundatb, 

 angulis, .superioribus leviter rotundatis, apice lato truncato et recto; 



binis intra sed juxta marginem 



vertice visis 



ellipticis. granulis magnis 



lateralem utrobique. 

 Long. 22/*; lat. 20/*; lat. isthm. 5*2/*; crass. 12/*. 

 Hab— Momauk, east of Bhamo (No. 21551). 



This variety should be compared with C. Eaabolieme Wille var. proiradum W. & G. 8. West, 



which it resembles very much in the shape of the semicells. 



t 



109. Cosmarium quadriverrucosum sp 



n. (PL xv, fig. 14). 



C. parvum paullo longius quam latum, profundissime coiistrictum, sinu angusto- 



' subampliato; semicellula3 late truncato-pyramidatas, angulis infenonbu 



lineari extremo 



et superioribus rotundatis, lateribus convexis, apice leviter eonrexo I membmim prauulis 



acutis subsparse dispositis ornata, 



in 



ambitu circiter'14; verrucis magnis binis (leviter 



5-angulatis) trans centrum 



semicellularnm ; a 



vertice visa? ellipticse, verrucis magnit 



v.; 



truncato-retusis binis ad medium utrobique 



Long. 23,*; lat. 2V, lat. isthm. § ^ J crass. 

 Hab.— In the Kan-gyi at Mudon (No. 24505). 



15/i. 



110. 



Cosmarium teiverrucosum sp 



n. 



(PL 



XV 



) 



C. parvnm, paene 



l|-plo longius 



quam 



latum, 



fig. 16). 



profundissime constnctum, sinu 



angusto-lineari extremo ampliato; 



semicellula? transverse oblongo-rectangulares, angulis 



Ann. Roy. Bot. Gakd. Calcutta Vol. VI. 



