“…Chromosome number of n = 15 has been reported so far in N. stuartii (SARMA and KHAN 1965), n=27 inN. pseudoflabellata (present record) and n=36 in N. tenuissima (SARMA and RAMJEE 1967) and N. furcata (present record). The species with n = 15 and 27 may have originated due to hybridization between taxa with n=6 and n=9, and taxa with n=9 and 18 respectively although experimental evidence is yet to be adduced.…”