1990. Scale-bearing chrysophytes from tropical Northeast India. -Nord. J. Bot. 10: 343-354. Copenhagen. ISSN 0107-055x. This is the first publication describing scale-bearing Chrysophyceae from India by means of electron microscopy. 'henty seven such taxa are described from samples for ponds, rivers and thermal springs. 'henty of these are Mallomonas spp.: M . akrokomos, M. bronchartiana, M . caudata, M . ceylanica, M. costata, M. crassisquama, M. cyathellata var. cyathellata, M. cyathellata var. chilensis, M . cyathellata var. kenyana, M. gunata, M. heterospina, M . mangofera f. mangofera, M . mangofera f. foveata, M . mangoferea f. reticulata, M . matvienkoae f. matvienkoae, M . matvienkoae var. grandis, M. morrisonensis, M . peronoides, M . portae-ferreae, and M . tasmanica. Three are Synura taxa: S. curtispina, S. petersenii f. petersenii, and S. petersenii f. kufferathii. ' h o are Spiniferomonas species: S. coronacircumspina and S.enigmata. Paraphysomonas and Chrysosphaerella were each represented by one species: P. vestita and C. longispina. The water bodies from which these samples were taken were mostly eutrophic and nutrient rich. The majority of the taxa were obtained during the summer months when water temperatures were high. This contradicts the widely held belief that silica-scaled chrysophytes are mainly found in cold oligotrophic and mesotrophic waters. Mallomonas portae-ferreae and one unidentified species of Mallomonas were recorded also from thermal springs having water temperatures up to 50°C.

Sumnmry: An oligotrophic pond and a eutrophic pond of Bhagalpur, India, were studied for phytoplankton distribution and to establish the relationship between this distribution and the physico-chemical properties of the water. Altogether, 114 algal taxa werc identified. I n R.ekabganj pond, diatoms constituted 54.4 0,; of tho algal spccies followed by green algae (29.4 blue greens (11.7and euglenoids (2.9In Ramna pond, blue greens were the most dominant comprising 35.7 O/,, of algal species followed by green algae (32.8 diatoms (18.5 Oi0) and euglcnoids (8.5 o/o). The members of Dinophyceae, Chrysophyceae and Xanthophyceae were poorly represented in both the water-bodies. Aphanizomenon flos-aquae, Microcystis aeruginosa, Chlorella vulgaris, Cladophora crispata, Volvox aurew and Euglena spp. were recorded only in Rarnna pond, indicating its higher nutrient status. Dinobryon calciforntis, many pennate diatoinis a n d desmids, indicators of oligotrophy, were observed in Bekabganj pond only.Measurements of water properties in the t,wo ponds showed t h a t transparency, dissolved oxygen and silicate were higher in Rekabgnnj pond than inRamna pond, while total alkalinit>y, hardness, total dissolved solids, dissolvod organic mat,ter. different cations, phosphate, nit.ra,t'e und chloride were lower in Rekabganj pond than in Ramna pond. Iritrodu ctionAlthough relationships between phytoplankton and eutrophication of 11atiiraI waters have been studied by many aquatic biologists in temperate regions of t h e world, IittIe is known about trnpical water-bodies. Secchi disc readings (CARLSON; CANF~ELD and HODGSO w), nitrogen concentration, nitrogen to phosphorus ratio (BAKER et al.), phosphorus (HICKMAN) and many other parameters have been used as possible indicators of eutrophication.The present investigation was undertaken t o determine the differences in phytoplankton composition and physico-chemical properties between a eutrophic (Ranilia) water-body arid an oligotrophic (Rekabganj) water-body. The area of Ramna pond is 20,286 rnz and the mean depth is 2.2 m, while the area of Rekabganj pond is 1,591 m2 and the mean depth is 2.9 m. Both the perennial ponds are located in the northeastern part of India on the south hank of river Ganges a t 87O02' east longitiide and 25O15' north latitude.

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Summary:The present study deals with the comparative quality of potable waters of different sources at Bhagalpur, India, which is located on the south bank of river Ganga at 87'02' N latitude and 25'15' E longitude. Surface water (river Ganga) receives a number of drains and domestic wastewater outlets. The municipal surface water gets severely contaminated by rusted, damaged parallel pipelines and the groundwater through seepage from septic tanks, drains and a deep sewerage system. The contaminants from these sources have deteriorated the quality of potable water by increasing the concentration of turbidity (40 NTU), nitrate-N (42.5 ppm), total bacterial density (21.649 X 107/1) and MPN coliform (12,900/100 ml). The higher concentration of nitrate-N, chloride and the presence of E. coli, Staphylococcus aureus, Proteus vulgaris, Salmonella typhii and Pseudommas aeruginosa indicated the faecal contamination.

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