The method of Legendre polynomials was used to obtain features characteristic for the shape of the diatoms pertaining to Sellaphora pupula taxa. Along with other characterisitcs and analyses, five new species were evidentiated.

In this chapter we present an improved method for contour profiling which is based on dynamic ellipse fitting. We also apply Legendre polynomials for characterizing upper and lower contour parts, assuming that a contour with a pennate form is in horizontal position. Three classification methods are used: decision trees, backpropagation neural networks, and a hand-optimized syntactical classifier. Using only contour features of the Sellaphora pupula