Cómo aplicar un grupo de marcadores de folletos usando capas

Estoy tratando de aplicar elLeaflet.MarkerCluster.LayerSupport. Pero no sé cómo usarlo :( Ya he leído la documentación sobre pero e intenté muchas veces pero no funciona.

Este es mi codigo

<!DOCTYPE html>
<html>
<head>
    <title>Península</title>
    <meta charset="utf-8" />

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet/v0.7.7/leaflet.css" />
</head>
<body>
    <div id="map" style="width: 600px; height: 400px"></div>

    <script src="http://cdn.leafletjs.com/leaflet/v0.7.7/leaflet.js"></script>
    <script src='https://api.mapbox.com/mapbox.js/plugins/leaflet-markercluster/v0.4.0/leaflet.markercluster.js'></script>
    <script src="leaflet.markercluster.layersupport-src.js"></script>


    <script>        

        var NemachIcons =L.Icon.extend({
            options:{
                shadowUrl:'',
                iconSize:   [50,55],
                iconAnchor: [45,45],
                popupAnchor:[-3,-76]
            }
        });

        var tiloIcon = new NemachIcons({iconUrl:'http://www.iconshock.com/img_jpg/SIGMA/general/jpg/256/pyramid_icon.jpg'}),
            puebloIcon = new NemachIcons({iconUrl:'http://icons.iconseeker.com/png/fullsize/gant/pointless-bw-circle-i-use-it-iex.png'}),
            gasIcon =new NemachIcons({iconUrl:'https://cdn2.iconfinder.com/data/icons/function_icon_set/circle_green.png'});


        L.icon =function (options) {
            return new L.Icon(options);
        };


        var sitios = new L. LayerGroup();

        L.marker([20.683, -88.568], {icon: tiloIcon}).bindPopup('1').addTo(sitios),
        L.marker([21.204547, -89.269466], {icon: tiloIcon}).bindPopup('2').addTo(sitios),
        L.marker([20.332362, -89.647899], {icon: tiloIcon}).bindPopup('3').addTo(sitios),
        L.marker([20.486417, -88.660218], {icon: tiloIcon}).bindPopup('4').addTo(sitios),
        L.marker([21.151196, -87.958143], {icon: tiloIcon}).bindPopup('5').addTo(sitios);


        var pueblo = new L.LayerGroup();

        L.marker([20.9330, -89.0178], {icon: puebloIcon}).bindPopup('6').addTo(pueblo),
        L.marker([20.6909, -88.2015], {icon: puebloIcon}).bindPopup('7').addTo(pueblo);

        var gas = new L.LayerGroup();
        L.marker([20.973907, -89.578931], {icon: gasIcon}).bindPopup('8').addTo(gas);


        var mbAttr = ' ' +
                '' +
                '',
            mbUrl = 'https://api.tiles.mapbox.com/v4/{id}/{z}/{x}/{y}.png?access_token=pk.eyJ1IjoibWFwYm94IiwiYSI6ImNpandmbXliNDBjZWd2M2x6bDk3c2ZtOTkifQ._QA7i5Mpkd_m30IGElHziw';

        var grayscale   = L.tileLayer(mbUrl, {id: 'mapbox.light', attribution: mbAttr}),
            streets  = L.tileLayer(mbUrl, {id: 'mapbox.streets',   attribution: mbAttr});

        var map = L.map('map', {
            center: [20.794527, -88.760612],
            zoom: 8,
            layers: [grayscale, sitios]
        });

        var baseLayers = {

            //"Grayscale": grayscale,
            //"Streets": streets

        };

        var overlays = {
            "Pirámide": sitios,
            "Poblado": pueblo,
            "Servicio": gas
        };

        L.control.layers(baseLayers, overlays).addTo(map);
    </script>
</body>
</html>

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