This paper comprises the results of investigations on the algal flora of the hot springs at Aravali, Tooral, and Rajewadi, in Sangmeshwar taluka of Ratnagiri district . A total of 31 (two diatoms, the rest bluegreen algae), 12 (seven diatoms, the rest blue-green algae) and 52 (41 diatoms, the rest blue-green algae) taxa have been recorded from the Aravali, Tooral, and Rajewadi springs respectively . These include one new variety and four new forms . The specimens have been preserved in the Blatter Herbarium, St . Xavier's College, Bombay .
The Aravali spring is about 194 miles from Bombay on the Bombay-Konkan-Goa road . There is only one hot spring flowing into a tank . A temperature of 41ยฐC has been recorded, with the water flowing at the rate of about 1,800 litres per hour . Six miles ahead of the Aravali spring is the Tooral hot spring situated at a distance of about 90 metres off the main road . There is only one spring flowing into a dilapidated tank . The water flows at the rate of about 4,500 litres per hour . A temperature of 60ยฐC to 61ยฐC has been recorded . The spring at Rajewadi is two miles away from Tooral . Water flows at the rate of about 2,300 litres per hour into a main tank from which it overflows into an adjoining small tank . The temperature of the water of the main tank varied from 48 .5ยฐ C to 49ยฐ C. The springs were visited thrice during 1960-1961 in the months of June, December, and September in that order . The taxa marked with an asterisk have been recorded and described earlier by the authors in other hot springs (THOMAS & GONZALVES, 1965, 1965a, 1965b) . ALGAL FLORA OF THE HOT SPRING AT ARAVALI BACILLARIOPHYCEAE 1 . Caloneis fasciata (LAGST .) CLEVE* At 41ยฐC . 2 . Pinnularia microstauron (EHR .) CLEVE var. microstauron* At 41ยฐC . CYANOPHYCEAE 3. Chroococcus westii (W . WEST) BOYE-PETERSEN * At 41ยฐC . 4 . Chroococcus schizodermaticus WEST* At 41ยฐC . 5 . Chroococcus minutus (KiTZ .) NAG.* At 41 ยฐC . 6 . Chroococcus membraninus (MENEGH .) NAG.
Cells without sheath 3 .5-8 ,u in diameter, with sheath 4-10,u in diameter .
This alga agrees well with the type, but differs in having a stratified sheath. In this respect the form agrees with that of PETERSEN (1946) .
At 41ยฐC .
7 . Chroococcus minor (KUTZ.) NAG .* At 41ยฐC.
8 . Gloeothece palea (KiiTZ .) RABENH.
Cells without sheath 2 .2-3 .6 ,u in diameter, 3-6 ,u long, with sheath 8-14 j in diameter. Sheath hyaline to light yellow, lamellated .
This form differs from the type in having a lamellated sheath . At 41ยฐC .
9 . Gloeothece geoppertiana (HILSE) FORTI
Cells without sheath 2 .4-3 .4 ,u in diameter, one and a half to twice as long as broad ; sheaths colourless, diffusing into one another .
At 41ยฐC .