The present communication deals with the description of a new species of Anabaenopsis (A . venkataramanii sp . nov .) collected from Najafgarh Jhil near New Delhi (India) during May, 1958 . The alga was abundant near the shores where it formed blue green scum on the surface along with Diplocystis aeruginosa .
The trichomes are 1-22 times spirally coiled (fig . 6) . The spirals are 16-28.8,u long . The direction of the coiling is either clock wise or anticlock wise, but the coiling of a particular trichome is in one direction only. Sometimes due to the pressure of cover glass the spirals get elongated and are thrown into many-folds, thus giving a false impression of reversal of the spirals (fig . 1) .
The trichomes are without an envoloping sheath . The cells are barrel-shaped but sometimes cylindrical, 5 .7-9.6,u broad and 5.7-6.8 (-9.6),u long. The thickness of each individual trichome is uniform throughout its length. The cross wall regions are constricted . The cell contents are blue green in colour and granular with pseudovacuoles. The cell division takes place by the usual constrictive division about the middle of the parent cell (figs . 4 and7).
Heterocysts are both terminal and intercalary, the former being single pored and situated one at each end of the trichome (figs . 1, 2, 3, 4, 5 & 7) . The intercalary heterocysts are always in pairs (fig . 4) . The heterocysts are spherical, 5 .7-7.6 ,u in diameter and are provided with a thick wall composed of an outer and an inner envelope . At the polar regions of the heterocysts is commonly seen a fine refractive granule .