38. Ona new species of Cylindrospermum from Bengal— 
Cylindrospermum doryphorum, 
Brith! et Biswas. 
By Pavt Briint anp Katrpapa Biswas. 
[ Paper read at the meeting of the Asiatic Society of Bengal on the 
7th of March 1923. ] 
The genus Cylindrospermum belongs to the Tribe Ana- 
baeneae of the family of Nostocaceae. Dr. Forti, in De Toni’s 
Sylloge Myxophycearum, page 47]. defines the genus as 
follows :~- 
a stratum of indefinite outline, the cylindrical form of the cells 
and particularly of the spores, which, w ere they occur, are 
placed singly, rarely several in a row, immediately behind the 
terminal heterocyst. : 
n our species the heterocysts are found one at either end 
of the filament. The filaments are, however, brittle, and it can 
often be observed under the microscope that one or both of the 
heterocysts, together often with one or two of the adjacent 
vegetative cells break off, after which the residual filament is 
left with only one or no heterocyst at either one or both the 
rounded or pointed ends. As a matter of fact, if a small 
iari i isti i the he 
green. A peculiarity which distinguishes b 4 
i Nos is the shape 
our species from those of most of the No acraanecceine “esl 
which the heterocysts are pear-sh 
outer end, and in Cylindrospermum Goetzet the heterocysts are 
