This interactive scatter plot visualizes the Iris dataset, mapping sepal length against petal length. Each point is colored and shaped by species, with a custom legend explaining the symbols. The visualization uses D3 version 7, employing the `symbol()` API from `d3` to generate distinct mark shapes, `scaleLinear` for axes, and `scaleOrdinal` for the categorical species mapping. Data is loaded from a remote GitHub CSV file and parsed with `csvParse`. The chart is rendered using an SVG canvas.